[Regarding] your criticisms of my Time paper. I am more grateful than ever for your kindness in giving me such a full statement.

I hope we shall get a chance to talk it over soon…

I am interested to realise that you and Russell each half agree with me. He says that the A series is unreal, but that it is not necessary for time. You say it is necessary for time, but not unreal. (McTaggart to Moore, 3 January 1909¹)

1 Introduction

Early analytic philosopher G E Moore is not known for his metaphysics of time. Within Moore scholarship, his metaphysical views on time are under-studied;² within the philosophy of time, his views are omitted.³ This paper focuses on Moore’s most substantial, realist discussion of time, advanced in a set of 1910–11 lectures, later published as Some Main Problems of Philosophy (Moore 1953, hereafter, Main Problems). I show these lectures defend a Common Sense⁴ realism about time, presentism, and A-theory. Moore is not currently recognised as a presentist or an A-theorist, yet appreciating that he held both positions is important. I argue that Moore offers the earliest sustained defence of presentism in English-language philosophy. And, if Bertrand Russell is the ‘father’ of B-theory,⁵ Moore is the ‘father’ of A-theory. As the letter above shows, even J M E McTaggart, who famously distinguished the A- and B-series, believed that, with regard to their reality, Russell and Moore ‘each half agree with me’.

The paper proceeds as follows. §2 sets the scene, describing Moore’s early career, key questions in the metaphysics of time, and Moore’s writings about time. It stresses his intellectual relationships with McTaggart and Russell, figures who will reemerge throughout this study. It also explains that during the late nineteenth and early twentieth century, many British philosophers – including, initially, Moore – were anti-realists about time. §3 turns to Main Problems. The first part of this section sets out Moore’s new, positive and negative arguments for temporal realism, grounded in Common Sense. The second half shows that Main Problems intertwines this Common Sense realism with presentism and A-theory. §4 argues that Henry Sidgwick is a major source of Moore’s newfound, Common Sense position. In (what I believe to be) the first discussion of Sidgwick’s posthumously published 1905 lectures on time, I show that Sidgwick anticipates Moore’s positive and negative arguments for temporal realism from Common Sense. He may even share Moore’s presentism and A-theory. Finally, §5 considers Moore’s legacy with regard to time. First, I show that Moore promoted the rejection of anti-realism about time with the rejection of British idealism, thus bundling the rejection of both positions together. Second, I consider Moore’s influence over later philosophy of time: I suggest he may have spurred Russell’s development of B-theory, and show that Moore may have had a hand in widespread contemporary characterisations of A-theory and presentism as ‘commonsensical’. Finally, I argue that Moore’s presentism and A-theory deserve a place in our histories.

2 Scene Setting: Moore, Time, and Moore on Time

2.1 Moore’s Early Career: Relationships, Idealism, and Realism

Moore (1873–1958) went up to Trinity College, Cambridge in 1892. He followed Russell (1872–1970), who had arrived in 1890, and McTaggart (1866–1925), who had arrived in 1885. After graduating in 1896, Moore aimed to follow McTaggart and Russell in winning a Trinity Prize Fellowship, a venture that did not succeed in 1897, but did in 1898. Both Fellowship applications required a dissertation; these were posthumously published. Moore’s Fellowship ran from 1898 to 1904. After it ended, Moore moved to Edinburgh, and then to London. In the winter of 1910–1911, he gave a series of public lectures in London, and it is these that were published – over four decades later – in 1953 as Some Main Problems of Philosophy. Later in 1911, Moore returned to Cambridge, staying until retirement in 1939.⁶

Moore and Russell met during Moore’s first year at Cambridge. During these early Cambridge years, both came to embrace idealism – Russell (1967: 53) implies that the idealist McTaggart was partly to blame.⁷ Russell held idealism from around 1893 (Griffin 1991: 50), and Moore from around 1895 (Regan 1986: 70). Russell writes of this period:

All the influences that were brought to bear upon me were in the direction of German idealism, either Kantian or Hegelian, with one single exception… Henry Sidgwick…. At the time, I, in common, with other young people, did not give him nearly as much respect as he deserved. We called him ‘Old Sidg’ and regarded him merely as out of date…. I went over completely to a semi-Kantian, semi-Hegelian metaphysic. (Russell 1959: 38)

Sidgwick was such an old realist that the soon-to-be new realist Russell regarded him as out of date. More on Sidgwick below.

Russell left Cambridge in June 1894 but Moore’s autobiography records that for ‘some six or eight years after’ they used to meet ‘frequently’ and discuss philosophy: ‘In these discussions, there was, of course, mutual influence’ (1942: 15). In 1898, Moore and Russell began rejecting idealism. Although their relationship would become increasingly strained, as part of their rejection of idealism the pair produced pivotal, interconnected pieces of early analytic philosophy.⁸ Moore’s autobiography locates the crucial break from idealism in his second, 1898 Fellowship dissertation:

this was the beginning, I think, of certain tendencies in me which have led some people to call me a ‘Realist’, and was also the beginning of a breakaway from belief in Bradley’s philosophy, of which, up till about then, both Russell and I had, following McTaggart, been enthusiastic admirers. (Moore 1942: 22)

Thomas Baldwin, who has studied Moore’s early work extensively, explains that this dissertation, submitted in September 1898, ‘distinguishes sharply, as idealists do not, between thought and its objects’ (Baldwin 2004). Russell (1959: 54) credited Moore with coming to this realism first: ‘It was towards the end of 1898 that Moore and I rebelled against both Kant and Hegel…. Moore led the way, but I followed closely in his footsteps’. Their shared ‘new realism’ would come to be known as ‘early analytic philosophy’.⁹ By 1906, the conflict between realists and idealists was so embedded that J S Mackenzie (1906) titled a Mind article, ‘The New Realism and the Old Idealism’.

Moore’s biography explains that after their initial work on realism, he and Russell saw less of each other: ‘After about 1901 we met but rarely… until, from 1911 to 1915, we were both of us lecturing in Cambridge, and both had rooms in Trinity’ (1942: 15). During this latter period, when Moore, Russell and McTaggart were all once again at the same college, they were memorably dubbed ‘The Mad Tea Party of Trinity’.¹⁰

This brings us to McTaggart. Their near-contemporary, McTaggart taught Moore and Russell, and all three were initially friendly. McTaggart’s friendship with Russell ended during the first world war.¹¹ However, Moore and McTaggart remained friends throughout their lives. Of all his philosophy teachers, Moore’s biography states he was ‘undoubtedly’ most influenced by McTaggart:¹²

He produced the impression of being immensely clever and immensely quick in argument, but I think that what influenced me most was his constant insistence on clearness – on trying to give a precise meaning to philosophical expressions, on asking the question ‘What does this mean?’. (Moore 1942: 18–19)

In support of Moore’s job application for a Chair at Glasgow, McTaggart wrote on 6 June 1920:

I have no hesitation in saying that I regard Dr G E Moore as unsurpassed in ability by any British philosopher now living. There are others who may well be his equals, but I know of none whom I shall consider as his superiors.¹³

Their extant correspondence shows that they continued to informally read and comment on each other’s work until at least 1923, two years before McTaggart’s death.

2.2 Some Metaphysics of Time

This paper is concerned with three questions about time. The first question regards its reality: Is time real? If time is unreal, I take it that, fundamentally, no temporal relations hold between anything: nothing is, say, before, or future, to anything else. Moore himself puts this point with flair:

If Time is unreal, then plainly nothing ever happens before or after anything else; nothing is ever simultaneous with anything else; it is never true that anything is past; never true that anything will happen in the future; never true that anything is happening now; and so on. (Moore 1918: 112)

If time is real, we can ask our next two questions, concerning its nature.

The second question asks, Do past, present, or future things exist? One answer to this is presentism. In the Stanford Encyclopedia of Philosophy entry on ‘Time’, this position is characterised as follows: ‘According to presentism, only present objects exist’ (Emery, Markosian, and Sullivan 2020: §6). If we were to make an ‘accurate’ list of all existents, present things such as yourself and the Taj Mahal would be included, but Socrates and future Martian outposts would be excluded. In contrast, eternalism holds ‘that objects from both the past and the future exist’. The eternalist’s list of existents would include present objects such as the Taj Mahal, and ‘non-present objects’ like Socrates and future Martian outposts.¹⁴

The third question asks, Is time best characterised as an A-series or B-series? This debate is rooted in McTaggart’s 1908 ‘The Unreality of Time’, which distinguishes two ways of ordering events in time:

I shall speak of the series of positions running from the far past through the near past to the present, and then from the present to the near future and the far future, as the A series. The series of positions which runs from earlier to later I shall call the B series. (McTaggart 1908: 458)

In the 1960s, Richard Gale argued that, in light of McTaggart’s distinction, his commentators divide into the following camps. The ‘A-theory Answer’ holds, ‘the A-series alone is sufficient to account for time’. In contrast, the ‘B-theory Answer’ holds, ‘The B-series alone is sufficient to account for time’ (Gale 1966: 146). Gale’s characterisation of the A-theory and B-theory took hold, and which (if either) of these positions should be preferred is still widely debated today. The Stanford Encyclopedia of Philosophy ‘Time’ entry characterises the debate as follows:

McTaggart… [distinguishes] between time conceived of as a B-series (events ordered by which come before and which come after) and time conceived of as an A-series (events ordered by which are present, which are past, and which are future)…

B-theorists think all change can be described in before-after terms…

A-theorists, on the other hand, believe that at least some important forms of change require classifying events as past, present or future. (Emery, Markosian, and Sullivan 2020: §5)

As I read Moore, he weighs in on all three of these questions.

2.3 An Overview of Moore’s Writings on Time

This section offers an overview of Moore’s writings on time, from 1897 onwards. Moore began working on the topic during a period of exceptional interest in it: late nineteenth century British philosophy saw an explosion of work on time. This was partly fuelled by the British idealists, many of whom developed complex metaphysics to defend its unreality.¹⁵ For example, T H Green’s Prolegomena to Ethics (2003: 63) argues that ultimate reality comprises an eternal consciousness, to which before and after, and time itself, is an appearance. Bradley’s Appearance and Reality argues at length that time is ‘a contradictory appearance’ (1893: 43). McTaggart’s work also belongs to this tradition. He first defended the unreality of time in a two-part 1893–94 piece, ‘Time and the Hegelian Dialectic’: ‘There is then nothing obviously impossible in the supposition that… reality is one timeless whole’ (1894: 192).

Moore’s earliest interest in time seems due to McTaggart. Moore describes their first meeting in a letter to his mother dated 18 March 1893:

Last Sunday evening I was taken to [a party]… most of the time, I was listening to MacTaggart, a fellow of Trinity for metaphysics, who is very interesting…. On Friday I went out to breakfast and met MacTaggart again: he spent nearly an hour in trying to explain to me the metaphysical aspect of ‘time’.¹⁶

Almost fifty years later, Moore’s autobiography returns to the topic:

Russell had invited me to tea in his rooms to meet McTaggart; and McTaggart, in the course of conversation had been led to express his well-known view that Time is unreal. This must have seemed to me then (as it still does) a perfectly monstrous proposition, and I did my best to argue against it. I don’t suppose I argued at all well; but I think I was persistent, and found quite a lot of different things to say in answer to McTaggart. (Moore 1942: 13–14)

Either Moore changed his mind over the next few years, or he is misremembering his initial reaction to McTaggart’s ‘well-known view’, for in fact Moore defended the unreality of time in several early writings, including his very first publication.

This comprised Moore’s contribution to an 1897 Aristotelian Society symposium, ‘In What Sense, If Any, Do Past and Future Time Exist?’. The close of Moore’s paper gives a flavour of his anti-realism:

Time must be rejected wholly… if we are to form an adequate notion of reality; and this thorough-going rejection of almost all the content with which our world is filled, most seriously impairs the filling of our conception of reality. We are, I think, forced with Kant and with Lotze, to desiderate an entirely different form of Perception [to understand reality]… this Reality for us remains little more than a Ding an Sich. (Moore 1897: 240)

For Moore, our world is filled with contents that are in time. If we reject time, we ‘seriously impair’ our conception of reality. Without some new form of perception that could reveal the nature of timeless reality, reality remains an unknowable, Kantian Ding an Sich (thing-in-itself). Moore desires such a new form of perception, to better understand timeless reality.

Moore holds fast to this view in several further writings. His two Fellowship dissertations are of particular interest to us, for they reveal his fascination with Kant’s first antinomy – a fascination which would persist into Main Problems. This antinomy comprises a pair of opposing arguments seeking to show that time is a form of thought. One argument claims that the world must have a beginning in time, for it is impossible that there should exist an infinity of events before the present moment. The other argument claims that the world cannot have a beginning in time, for every event is preceded by another event.¹⁷ As these arguments produce a contradictory conclusion, we should consign time to appearance. Moore’s 1897 Fellowship dissertation accepts this: ‘objects in space and time are not the world as it really is’, and ‘to treat them as such would lead to irreconcilable contradictions’ (2011: 33). Citing his symposium piece, Moore explains, ‘I have tried to justify a notion of reality, which excludes time’ (2011: 71–72). Although Moore’s 1898 Fellowship dissertation marked Moore’s turn from idealism to realism, it seemingly took him longer to turn from temporal anti-realism to temporal realism. In this second dissertation, Moore makes various new remarks on Kant: ‘the Antinomies prove that our conception of the world, as in space and time, is not a true one’; ‘The antinomies cannot be solved’ (2011: 152, 156). On the basis of such claims, Baldwin (2010: 3) writes that in this 1898 dissertation Moore ‘still endorses Kant’s arguments for the unreality of space and time’ (see Baldwin and Preti 2011: lviii). I agree.

Within two years of submitting his 1898 dissertation, Moore became a realist about time. For example, his paper ‘Necessity’ (1900) claims, without qualification, that every thing ‘existed at some moment of time’. Further, once Moore became a temporal realist, he began attacking temporal anti-realism. In 1901, McTaggart published Studies in Hegelian Cosmology; Moore responded to this in two lengthy book reviews. Both are courteous and respectful in tone. For example, Moore’s first review opens with lengthy praise for the book’s ‘rare’ and ‘valuable’ combination of merits’, including its ‘most unusual clearness’ (1902: 177). ‘Mr. McTaggart’s reasoning’, it observes, ‘is inferior to none in ability’. Yet both reviews lambast McTaggart’s anti-realism about time. In the first review, Moore (1902: 189–90) protests, ‘though Mr. McTaggart obviously assumes that to exist timelessly and to exist throughout time are at least compatible, we must (till further informed) regard it as a contradiction’. In the second review, Moore argues that as our ethical actions are in time, if ‘what exists timelessly is the sole reality’, then ‘neither our actions nor what they produce can be real’ (1903b: 341–42). This would lead to the untenable result that our good actions are valueless: ‘the unreal existence of one thing rather than another… can certainly not have any value’. The idea is that our ethical actions take place in time: if time is unreal, they are unreal, and thus lack value. Similarly, Moore’s Principia Ethica claims that ‘the most characteristic doctrines of Metaphysics’ have a ‘purely negative bearing’ on practical ethics, for they hold that only ‘eternal reality exists… nothing else is real – that nothing either has been, is now, or will be real in time’ (1903c: 115–16). Moore takes it to ‘truly’ follow from this ‘that nothing we can do will ever bring any good to pass’. Principia Ethica does not name McTaggart here, yet he surely has him in mind.

Given Moore’s engagement with the philosophy of time prior to 1910, it should be apparent that he was well-equipped to tackle the topic in his Main Problems. These lectures contain, by far, Moore’s most detailed realist account of time. After delivering these lectures, he rarely returned to time in his published work. An exception is Moore’s 1917–18 ‘The Conception of Reality’, which briefly critiques Bradley’s anti-realism about time; although, as Baldwin (2010: 22) notes, this paper ‘obviously’ incorporates material from (the then unpublished) Main Problems. For example, Main Problems (1953: 208–9) accuses Bradley of contradiction, arguing that when Appearance and Reality claims time is ‘not real’, it is committed to theses that contradict Bradley’s further claim that ‘in some other character… time may be real’. This critique is echoed Moore’s ‘The Conception of Reality’ (1918: 112). Moore also returned to time in private notebooks: his posthumously published Commonplace Book (1962) contains entries on events, change, and the present.¹⁸ The interest in time that McTaggart sparked in Moore, perhaps over a breakfast of tea and crumpets, proved long-lasting.

3 Main Problems on Common Sense Realism, the A-Theory, and Presentism

3.1 Moore’s Common Sense Realism

Main Problems presents three interconnected Common Sense views about time: realism, A-theory, and presentism. This section focuses on realism. Moore took this to be hugely important. Reflecting on its title, Lecture XI, ‘Is Time Real?’, states:

This question… whether it is true or not that immense numbers of different things in the Universe all have temporal relations to one another, seems to me by far the most important question which can be raised about the relation of Time to the Universe. And indeed it seems to me to be one of the most important questions which can be raised about the Universe at all. (Moore 1953: 202)

At this point in his career, Moore’s answer to this question is that time is real, things do bear temporal relations to one another. As I read it, Main Problems provides two kinds of argument for this realism, both drawn from Common Sense. One kind is positive: Common Sense supports realism. The other kind is negative: anti-realism about time violates Common Sense, and so should be rejected.

The positive argument appears first. In Lecture I (‘What is Philosophy’), Moore states, ‘the most important and interesting thing which philosophers have tried to do is… give a general description of the whole of the universe’ (1953: 1–2). He explains that

certain views about the nature of the Universe… held, now-a-days, by almost everybody [may] fairly be called the views of Common Sense’.

I wish, therefore, to begin by describing what I take to be the most important views of Common Sense: things which we all commonly assume to be true about the Universe, and which we are sure that we know to be true about it.

To begin with, then, it seems to me we certainly believe that there are in the Universe enormous numbers of material objects…. (Moore 1953: 2)

Moore’s other Common Sense views include that men ‘have minds’, and that all material objects are situated ‘in something which we call space’ (1953: 4–5). In this context, Moore sets out the Common Sense view of time:

That all material objects, and all the acts of consciousness of ourselves and other animals upon the earth, are in time. (Moore 1953: 11)

This is Moore’s positive argument: something ‘we are sure that we know to be true’ about the universe is that things are really in time. It is brief and blunt: everybody knows that things are in time. The philosophical heavy-lifting is undertaken by the negative arguments.

Let’s move on to those negative arguments from Common Sense. On my reading, they comprise two steps. On step one, Moore argues that anti-realists about time are implicitly committed to various views. On step two, he finds that these implicit views violate Common Sense, and so should be rejected. To get into the details, we must go deeper into Main Problems.

In the first lecture, having set out his views of Common Sense, Moore explains that even taken together, they don’t amount to a philosophical description ‘of the whole Universe’ (1953: 14). For example, Common Sense says that the universe contains some classes of things, but it doesn’t say that they are the only classes within the universe. For Moore, philosophical descriptions of the whole universe come in three kinds (1953: 17–18). The first kind add something to the views of Common Sense. For example, theists add ‘God’ to their description of the universe. Interestingly, Moore writes that philosophers who accept that material objects or acts of consciousness are in space and time ‘can hardly deny that there certainly are in the Universe also at least two other things… namely, Space and Time’ (1953: 16). On this view, ‘Space and Time themselves really are… they are something’, even though, unlike material objects or acts of consciousness, they do not seem to be ‘substantial’. Moore comments, ‘this view does seem to me to be a correct view’.

For Moore, the second kind of philosophical descriptions of the universe contradict at least some views of Common Sense (1953: 17–19). For example, sceptics deny that we can know whether material objects or other minds exist. The third kind of descriptions add to, and contradict, the views of Common Sense. Moore claims that this group contains ‘views which depart much further from Common Sense than any that I have mentioned yet’, and that they are ‘very much in favour amongst philosophers’ (1953: 17–20). Within this kind of descriptions, Moore includes the work of Berkeley, and of others who hold ‘views more startling still’, who say that ‘material objects, space, our acts of consciousness and time, are Appearances’ (1953: 21–22). Moore almost certainly has in mind the likes of Bradley and McTaggart. At the conclusion of his first lecture, Moore explains that he will ‘try hereafter to say something about as many of the points which I have mentioned as I have space for’ (1953: 27). In lectures with titles such as ‘Material Things’, and ‘Existence in Space’, Moore goes on to consider philosophical positions which supplement, or contradict, the views of Common Sense.

Regarding time, Moore makes a distinction between two incompatible views (1953: 201). One position, that I label Temporal Appearances, holds that things in time exist, as appearances. This view holds ‘there is such a thing as Time; and that ever so many different things do exist in it’, but these things, and ‘perhaps, Time itself’, are ‘in some sense, mere Appearances – Appearances of something else, which does not exist in Time at all’. The other position, that I label Unreal Appearances, holds that anything in time is unreal, including appearances. This view holds, ‘there is not really any such thing as Time at all; that nothing whatever really exists or happens in Time’. ‘Both these two views’, Moore writes, ‘present a very strange view of the Universe; and both, I think, might be said to contradict Common Sense’ (1953: 202). However, Moore finds Unreal Appearances especially problematic, as it ‘does quite plainly and flatly contradict an enormous proportion of our ordinary beliefs’.

With this background in place, let’s consider the negative argument from Common Sense against Kant found in Main Problems. In Lecture IX, ‘Existence in Time’, Moore recounts Kant’s first antimony: ‘the world must have had a beginning in time’ and ‘the world can have had no beginning in time’ (1953: 164). Moore reads this as producing the following result:

Kant’s two arguments, if they prove anything at all, prove this: namely, that if anything whatever exists at any time at all, then both of two contradictory propositions would be true. And since it is impossible that both of two contradictory propositions should be true, they prove… that nothing whatever really exists at any time at all. (Moore 1953: 169–70)

Moore wants ‘to insist’ that this is the result, because ‘both Kant himself, and others who have used similar arguments’, have not it seen clearly (1953: 170–71). Moore claims that Kant ‘sometimes speaks’ as though ‘anything which does exist in Time, must be a mere Appearance’. This position implies ‘that some things, namely, Appearances do so exist’. If this were so, Kant would hold the Temporal Appearances position. However, Moore argues, Kant is in fact committed to ‘the entirely inconsistent view, that nothing whatever – not even, therefore, a mere Appearance – can exist in Time’. In other words, Kant is committed to Unreal Appearances. And this, Moore argues, is a much more difficult position to hold:

once you realise quite clearly that what his arguments require you to admit, is… that absolutely nothing ever exists in Time at all, that, therefore, nobody ever believed anything at any time, or any one thing before another, and that all statements to the effect that anyone ever did do so are absolutely false – then, I think, you will find it much more difficult to admit this. That is why I wish to insist that what his arguments do prove, if they prove anything, is that nothing whatever, of any sort or kind, can possibly exist at any moment…

Kant’s arguments… prove that nothing exists in time at all. (Moore 1953: 171)

Moore accepts the foundation of Kant’s first antinomy:

To begin with, then, we are, I think, all commonly convinced that things do exist in time. For instance, we are convinced that some things do exist now, and that other things have existed before, in the past, which no longer exist now. There is hardly anything of which we are, in fact, more certain of than this. And I think it is quite plain, that if we are right about this, then something else is certain also: namely, that either some moment in the past must have been the first moment… or there must have existed before now an absolutely infinite series. (Moore 1953: 174–75)

Although Moore goes on to critique Kant’s arguments, he doesn’t outright reject them, rather acknowledging that they raise ‘real’ difficulties. The conclusion of this lecture asks, in light of the difficulties Kant raises, whether ‘we are entitled to conclude’ that the antinomy is successful:

especially, when there will follow… a further conclusion, which seems so obviously false, as that nothing can exist in time at all? that there is no such thing as time? It seems to me we are certainly not. (Moore 1953: 181)

I read Moore as saying that, no matter how compelling the antimony might be, we must not accept its conclusion, for it so radically contravenes Common Sense.

Similarly, consider the conclusion of Lecture X, ‘The Notion of Infinity’:

between 8 and 9 o’clock this evening an infinite number of divisible lengths of time… must have elapsed: and that time could ever arrive at 9 o’clock at all, if, before doing so, it had to pass over an infinite series, is just what Kant declares to be impossible. For my part, I do not know exactly what conclusion ought to be drawn from all these arguments…. But it does seem to me that we certainly are not entitled to draw the positive conclusion, which some philosophers have drawn, to the effect that there are no such things… as seconds, minutes, hours, and years. (Moore 1953: 200)

Again, Moore acknowledges the force of Kant’s arguments, and does not reject the arguments but their conclusion: these arguments do not entitle us to deny lengths of time such as minutes and years. When we pit Kant’s conclusions against the views of Common Sense, Common Sense wins out. Despite their gravity, there must be something wrong with Kant’s arguments.

3.2 Moore’s Common Sense presentism and A-theory

With the Common Sense realism of Main Problems established, let’s excavate its Common Sense presentism and A-theory. Having argued that all material objects and acts of consciousness are ‘in time’, Lecture I continues:

I say ‘are in time’; but, to speak more accurately I ought to say either have been in time or are so now or will be so in the future; either this, or else all three – both have been in time in the past, and are so now, and will be so in the future. For just one of the things which we mean by talking of ‘time’ is that there are such things as the past, the present and the future, and that there is a great difference between the three. None of the material objects in space and none of our acts of consciousness can, we hold, be truly said to exist at all, unless it exists at the time at which we say so; only those of them, for instance, which exist at the time at which I am now speaking can now be truly said to exist at all: of others, it may be true that they did exist in the past, or that they will exist in the future, but it cannot be true that they do exist. What I mean, then, when I say that all material objects and all our acts of consciousness are in time, is this: that each of them either did exist in the past, or exists now, or will exist in the future…

And I mean, too, that to say that a thing ‘did exist’ is something different from saying that it ‘does exist’, and both of these again from saying that it ‘will exist’; and that each of these different statements is in fact true of some things… [For example] of material objects: many have existed in the past, many do exist now, and many (in all probability) will exist in the future. I say we all commonly believe that these things are so. We believe that the three statements ‘It did exist’; ‘It does exist’; ‘It will exist’: are each of them true of many material objects and many acts of consciousness… And we believe, also, that one or other of these statements is true of all of them… the sun or the earth, for instance, both did exist, do exist, and (probably) will exist. This, I say, is certainly the belief of Common Sense. (Moore 1953: 11–12)

For Moore, Common Sense believes that all material objects and acts of consciousness have been, are now, or will be ‘in time’. For Moore, there is a ‘great difference’ between the past, present, and future. Having listed the most important ‘views’ of Common Sense, Moore adds a last ‘belief’ of Common Sense:

We believe that we do really know all these things that I have mentioned. We know that there are and have been in the Universe the two kinds of things – material objects and acts of consciousness… We know that things of both kinds have existed in the past, which do not exist now, and that things of both kinds do exist now, which did not exist in the past. All these things we should, I think, certainly say that we know. (Moore 1953: 12)

For Moore, a more accurate way of saying something is ‘in time’ is to say it is ‘in time… now’; or it was ‘in time in the past’, or ‘will be so in the future’. One of the things we mean by ‘time’ is that ‘there are such things as the past, the present and the future’. These remarks provide evidence that Moore is an A-theorist: that time requires an A-theory, and we must classify things as past, present, or future. Further, other remarks made in these passages suggest presentism: material objects and acts of consciousness cannot ‘be truly said to exist at all’ unless it is ‘at the time at which I am now speaking’. To illustrate, at the time when Moore was speaking, Julius Caesar did not exist. It is trivially true that in 1910, Caesar did not exist, and an eternalist would accept this. Yet Moore’s statement implies a more radical truth: in 1910, Caesar did not exist ‘at all’ – I take this to mean that Caesar did not exist simpliciter. An eternalist would certainly not accept this. Further, Moore argues that to say a thing ‘did exist’ is different to saying it ‘does exist’. For the presentist, there is indeed a major difference between these claims: a past thing does not exist simpliciter, whereas a present one does. In contrast, for an eternalist, to say of things that one ‘did exist’ and one ‘does exist’ is akin to saying that one thing is ‘here’ and another is ‘there’.

I find confirmation of Moore’s presentism in Lecture XVI, ‘Being, Fact and Existence’. Moore (1953: 291) asks what we mean by ‘being’, and argues it is that ‘which does belong to what we believe in, whenever our belief is true’. For example, if you believe that ‘I, while I look at this paper, am directly perceiving a whitish patch of colour’, then if your belief is true ‘there is such a thing as my being now directly perceiving a whitish patch of colour’. Moore also offers an characterisation of ‘being’:

[We may] say that to have being is equivalent to belonging to the Universe, being a constituent of the Universe, being in the Universe. We may say… that only what has being can be a constituent of the Universe: to say of anything that there is no such thing, that it simply is not, is to say of it that it is not among the constituents of the Universe, that it has no place in the Universe at all. (Moore 1953: 292)

However, Moore adds that this latter characterisation, that ‘being’ means ‘belonging to the Universe’, may be ‘inaccurate’. Precisely how illuminates his views on time:

Suppose it really is the case, as we commonly do suppose, that besides the things which are now there are some things which have been in the past, and are no longer now; and others which will be in the future, but are not yet. It seems quite plain that, of these three classes of things, it is only those which are now that actually have, in one sense of the word, the property of ‘being’: of those which were, but are no longer, it is only true that they did have it, not that they have it now; and similarly of those which will be, but are not yet, it is only true that they will possess it, not that they do possess it…

[Supposing this] there does arise a difficultly as to what we are to mean by the Universe. The difficulty is this: Are we going to say or are we not, that all the things which have been and will be do belong to the Universe – are constituents of it – just as much as those which are now? I think many people would say ‘Yes’: that the past and future do belong to the Universe just as much as the present does. And I think this is certainly one common sense in which we use the expression ‘the Universe’: we do use it to include the past and future as well as the present. But if we are going to say this, then, you see, we must admit that… ‘belonging to the Universe’ is not strictly equivalent to ‘being’. (Moore 1953: 293–94)

For Moore, it seems ‘quite plain’ that only things ‘which are now’ have the property of ‘being’: they possess that which belongs to the subject of true beliefs; they belong to, and are in, the universe. In contrast, past and future things lack ‘being’. This is why, if our understanding of the ‘Universe’ is broad enough to include past and future things, then ‘being’ is not strictly equivalent with ‘belonging to the Universe’. This broad understanding of the universe includes things lack being. For Moore, only present things have being. The point can be put in another way, as follows. Moore (1953: 300) holds ‘being’ to be the same as ‘exists’. Thus, Moore holds that only present things exist.

Immediately following his discussion of whether past and future things belong to the universe despite lacking being, Moore asks whether anything can have being ‘in some timeless sense’. He considers two kinds of philosophers who have answered this question affirmatively. The first kind ‘believe that the only sense in which anything can be at all is some timeless sense’. Presumably, this first camp includes anti-realists about time, such as Bradley and McTaggart. The second kind of philosopher believes ‘there has been a past, is a present, and will be a future’, and in addition there is ‘a timeless sense’ of the word ‘is’:

[They believe] there are many other things also belonging to the Universe, which are and yet are not now. In other words they believe that ‘being’ is a property which… belongs in some timeless sense to many things, to which it does not belong now. I am not at all sure, whether these philosophers are right or not. For my part, I cannot think of any instance of a thing, with regard to which it seems quite certain that it is, and yet also that it is not now. But we must I think admit that the alternative is a possible one: that the very same property called ‘being’ which did belong and will belong to things, to which it does not belong now, may also belong in some timeless sense to things to which it does not belong now. (Moore 1953: 294)

Moore doesn’t tell us which philosophers fall into this second camp. Perhaps he has in mind theists who hold that God exists timelessly; or Platonists who take universals to have a kind of timeless being.¹⁹ Moore doesn’t endorse this second position – he ‘cannot think’ of any things which exist timelessly – but he acknowledges it as a possible stance. One might think this position is incompatible with presentism, given the description of presentism I provided above: ‘According to presentism, only present objects exist’. This could be taken to mean that presentists reject the existence of past and present objects, and timeless objects. However, many thinkers have defended presentism alongside a timeless God, or Platonism about mathematical objects.²⁰ Presentism denies being to past and present objects, yet it is open to timeless ones.

When Moore wrote Main Problems its position was novel. Common Sense tells us that things ‘are in time’, that there are ‘such things as the past, the present and the future’, and that only things existing ‘now’ exist at all. In so doing, Common Sense bundles together realism about time, A-theory, and presentism.

4 Henry Sidgwick as a Key Source of Moore’s Common Sense Realism

Like Moore, Cambridge philosopher Henry Sidgwick (1838–1900) is not known for his metaphysics of time. Indeed, I am not aware of any scholarship on this aspect of his thought. The opening line of his entry in The Stanford Encyclopedia of Philosophy states, ‘Henry Sidgwick was one of the most influential ethical philosophers of the Victorian era’ (Schultz 2024, my emphasis). Yet his output ranged far beyond ethics, and included metaphysics. This section argues that Sidgwick’s work was a major source for Moore’s Main Problems.

Sidgwick’s most detailed defences of time realism can be found in two late texts. One is an 1894 Mind article, ‘A Dialogue on Time and Common Sense’ (Sidgwick 1894, hereafter, ‘Dialogue’). The other is a Cambridge lecture course on ‘Metaphysics’, which ran in the academic years 1898–99 and 1899–1900.²¹ The lectures were posthumously published in a 1905 volume edited by James Ward, Lectures on the Philosophy of Kant and other Philosophical Lectures & Essays (Sidgwick 1905, hereafter, Lectures). I argue that Sidgwick’s Common Sense arguments for time realism anticipate both Moore’s positive and negative arguments.

Sidgwick straightforwardly offers a positive, Common Sense argument for realism about time. This first appears in Sidgwick’s ‘Dialogue’. In the dialogue, Sidgwick (1894: 442–43) recounts meeting an unnamed ‘Russian Professor of Philosophy’, who says: ‘you think Time really exists as a condition of things, and not merely as a form of perception’. Sidgwick confirms that this is his position:

If Time is unreal, succession is unreal: and if succession is unreal, the interest of the study of the past is destroyed…. For the interest of human history lies not merely in the general laws of change that we can discover in it, but in the general fact of progress through stages each different from the one before. If time is unreal progress is unreal, and if progress is unreal the interest goes. (Sidgwick 1894: 444)

In response, the Russian Professor asks how Sidgwick will ‘get over’ Kant’s antinomies. Our Cambridge professor replies that he cannot, inferring ‘I do not comprehend past time as a whole’. ‘But’, Sidgwick adds, ‘to conclude therefore that time is unreal seems to me… to be “throwing out the child in emptying the bath”’. Sidgwick cannot ‘get over’ the antinomies, yet takes this to show there are things he does not understand, rather than following Kant in ‘throwing out’ the reality of time (1894: 443–44).

A little later, the Russian Professor contends that the ‘knowing subject’, human minds, are ‘out of time’ (1894: 445). Against this, Sidgwick reacts as follows:

While he was speaking, I took out my watch. ‘You say,’ I answered, ‘that you are more certain of your own existence than of anything else. Well, I am as certain as I am of my own existence that my ideas [of which we have been speaking]… occurred in succession between 5 and 6 minutes past 3 on the 20th of April 1894 – or at some other definite point of time, for my watch is not infallible – and, further, that these ideas would not have been what they actually were, had they not had as essential antecedents other ideas which have occurred before at definite points of time. Granting that Truth is not subject to change, my intellectual life is as much subject to it as any other element of my life.’ (Sidgwick 1894: 445–46)

For Sidgwick, our minds are continually subject to time and change. This argument from Common Sense for time realism would fit seamlessly into Moore’s 1910–11 lectures.

Sidgwick’s ‘Metaphysics’ lectures return to time, asking, How does there come to be a world of objects of experience for human minds? Sidgwick answers:

The Common Sense answer to this question is that this physical world has gradually come to be known through an innumerable mass of particular cognitions of material things, cognised as they exist apart from human minds; – such cognitions being remembered, recorded, communicated, combined, and finally rectified and generalised by Science… this world of empirical objects is certainly ordinarily conceived to exist in Space and Time: all our definite knowledge of it involves and is inseparable from spatial and temporal determinations. (Sidgwick 1905: 61–62)

Sidgwick contrasts his Common Sense answer with that of Kant, bringing us to his negative argument from Common Sense.

Sidgwick argues that Kant’s anti-realism about time is opposed to Common Sense, and thus should be rejected. Sidgwick characterises Kant as holding that space and time belong ‘only to percipient and conscious human minds’, not to ‘a real world existing independently of such perceptions’ (1905: 34). Before assessing this position, Sidgwick stresses its importance:

let us consider for a moment how momentous it is. I ask you to realise this, because I am not sure that Kant always realises it. For he seems to suppose that, even after being convinced by the arguments of the Transcendental Aesthetic… we shall still take a serious interest in the great questions of Rational Cosmology: – whether the physical world… had a beginning in Time… etc. But surely, for a mind of the least intelligence, all these questions are altogether cut off and precluded by the acceptance of the conclusions of the Aesthetic… For the real physical world… not being in Time, neither beginning, nor duration, nor succession of events can be predicated of it; and, neither changing nor enduring, it can have no causality, in the sense of necessary connexion of antecedents and consequents. (Sidgwick 1905: 34–35)

Sidgwick (1905: 35–36) explains that some pertinent conclusions, about ‘bodies’, are acknowledged by Kant. Yet, he argues, Kant is committed to further conclusions, about ‘spirits’ or human minds, that he does not acknowledge. For Sidgwick, if our spirits or minds are not in time and do not change, we do not progress:

The notion of spiritual progress is therefore merely phenomenal and unreal… And this, of course, applies to moral as well as to intellectual progress… [And] if moral progress is thus reduced to mere appearance, what becomes of the belief in the immortality of the soul which Kant… bases on it?… I do not find that Kant has fully contemplated these consequences of his doctrine of Time….

Well, the consequences, we see, are tremendous. (Sidgwick 1905: 36–37)

If moral progress is only an unreal, then the worth of Kant’s immortality is dubious. Sidgwick goes on to position Kant as being opposed to Common Sense. He points out that Kant cannot accept his ‘Common Sense’ answer to the question of how there comes to be a world of objects of experience for human minds:

from any such answer Kant is altogether precluded… [Because] Kant has already arrived at the conclusion that Space and Time do not belong to the world of reality, as it exists apart from human cognition… But this result is obviously very unlike our common world of material things in complex motion. (Sidgwick 1905: 62)

For Sidgwick, the consequences of Kant’s position are not merely momentous – they are so radical as to be implausible.

Having detailed Sidgwick’s Common Sense realism, I will show that Moore knew it well. Moore was in Cambridge when Sidgwick delivered his ‘Metaphysics’ lectures but he did not attend them. Moore’s autobiography writes:

[Of my philosophy lecturers] I think I gained least from personal contact with Sidgwick. His personality did not attract me, and I found his lectures rather dull. From his published works, especially, of course, his Methods of Ethics, I have gained a good deal, and his clarity and his belief in Common Sense were very sympathetic to me. But his lectures were, I think, too formal to be very interesting: he simply read out to us, not in a very stimulating manner, things that he had written in a finished form, fit for publication as they stood…. And moreover their subject-matter was not very interesting to me: they were what was subsequently published as Lectures on the Ethics of Green, Spencer and Martineau. (Moore 1942: 16–17)

In 1894, Moore attended Sidgwick’s lectures on ‘Ethical Systems’.²² And the last line of this passage implies that Moore only attended these lectures by Sidgwick. The passage as a whole explains why: having found Sidgwick’s earlier lectures dull, Moore would have been disinclined to attend his later ones. Despite disliking Sidgwick’s teaching style, Moore did like Sidgwick personally.²³

Although Moore did not attend Sidgwick’s ‘Metaphysics’ lectures, he would become closely familiar with these parts of Sidgwick’s work, for in 1906 he published a book review of Sidgwick’s Lectures. The review approvingly comments on the elements of Sidgwick’s view given above and, I argue, provides clear evidence that Moore’s subsequent position drew on Sidgwick’s. With regard to Sidgwick’s positive argument for time, Moore writes of his Common Sense realism:

Sidgwick claims (and I think he claims truly) that Common Sense believes matter to be real in precisely the same sense in which he himself believes it to be so…. [And] he means by ‘matter’ something of which, if it is real, it would be true to say that it has the qualities attributed to it by physical science – such qualities as ‘size, shape…, situation, and change of situation’…. [W]hen he asserts that ‘matter is real’ he does at least mean to assert that something non-mental really moves – that a portion of something non-mental is really situated in one position at one time, and in another at another time; so that to assert the reality of matter is to assert… also the reality both of space and of time. (Moore 1906: 687)

Main Problems advances precisely this thesis: Common Sense asserts the reality of matter, space, and time.

With regard to Sidgwick’s negative argument for time, Moore writes:

He takes Kant to have denied that any real things succeed one another in Time at all: Kant holds, he thinks, that of no two real things can it be truly said that one existed before the other… if Sidgwick is right… Kant, when he says that things with special properties are mere ‘phenomena,’ means not merely that they are ‘mental,’ but also that they are not real, even when we are conscious of them.

We may, then, state a clear issue as follows. Sidgwick maintains, at least, that something non-mental really exists at one time in one place, and at another in another; and that this is so, equally when we are, and when we are not conscious of it… Common Sense, as he claims, certainly agrees with him in believing this; and, no less, certainly, Kant, [T H] Green, and [Herbert] Spencer all fly in the face of common sense by denying it. (Moore 1906: 689)

For Moore, Sidgwick’s interpretation of Kant shows that, because time is unreal, anything in time is unreal – including phenomena. And this conclusion flies in the face of Common Sense. Again, Main Problems advances precisely this argument.

I also flag Moore’s reading of Sidgwick’s response to Kant’s first antinomy:

to this argument Sidgwick’s reply is very characteristic, and of a kind which should perhaps be commoner in philosophy than it is. He admits that he can find no flaw in certain arguments which urge that Time both must and cannot have had a beginning…. And he would also admit, apparently, that if these conclusions are sound, real things cannot exist in Time and Space. But he urges that the proposition that real things do succeed one another in time is at least as certain to him as the soundness of these conclusions: he is, he says in the ‘Dialogue on Time,’ as certain of it as of his own existence. (Moore 1906: 690)

Main Problems adopts a similar position: however compelling they may be, the conclusion of Kant’s antimonies should always be rejected in favour of Common Sense realism about time.

Given their shared views, I cannot help but conclude that Sidgwick’s Common Sense realism about time played a major role in shaping Moore’s. Yet Sidgwick’s name does not appear once in Main Problems, and Moore’s bibliography of his own writings omits his book review of Sidgwick’s Lectures; see Buchanan and Moore (1942). I find this perplexing.

There may also be an additional commonality between Sidgwick and Moore. Some of Sidgwick’s remarks imply he accepts presentism and A-theory. For example, in the ‘Dialogue’, the Russian Professor asks, ‘What do you think really exists?’. Sidgwick replies:

‘Do you mean,’ I said, ‘what really exists now? or do you include what has existed and what will exist?’

‘Ah,’ said he, ‘but that is a part of the question I am asking you. Do you think that the past really exists?’

‘Well,’ I said, ‘one has to distinguish different modes of real existence. It would be absurd to say that the great study of History is not conversant with reality. So far as the historian attains truth… the past exists for him as an object of thought and investigation: but so far as it is past it has ceased to exist in the sense in which the present exists.’ (Sidgwick 1894: 442–43)

This passage can be read as implying that the past only exists as the object of thought and investigation. If this reading is correct, then Sidgwick is defending something akin to presentism. Sidgwick’s ‘Metaphysics’ lectures hint at the same position, in the context of asserting that time changes:

For motion is a form of change; and Time is certainly thought to move: it seems to us as true to say that ‘Time flies’ as that ‘Time abides.’ In short, as I have said, change and permanence, succession and duration, seem to be inextricably combined in our common notion of Time: which, therefore, can only be properly imaged not by a line but by a point, the Present, passing along a line. (Sidgwick 1905: 101)

Sidgwick straightforwardly seems to a conceive a mind-independent, moving present: an A-theory. Precisely what he means by the claim that time moves and changes is unclear, but it might well refer to the presentist view that the universe changes from moment to moment, as time moves from moment to moment. It is possible Moore also read these views in Sidgwick, and took inspiration from them.

5 The Legacy of Moore’s Time Realism

This concluding section argues Moore’s realism about time is significant, in at least three ways. The first concerns the influence of Moore on the idealism-realism debate. In the 1890s, a small but diverse crew opposed anti-realism about time. Alongside Sidgwick, these included the humanist F C S Schiller, and the new realist Samuel Alexander.²⁴ Although none of these philosophers worked within the British idealist tradition, I have not found any evidence that their work drew battle-lines between British idealists and anti-realists about time on the one side, and new realists and realists about time on the other. Yet, in the early twentieth century, those lines became solidly drawn. As M F Cleugh would write in her vintage study of time, ‘On the whole… idealists are much more solidly against the ultimate reality of time than realists are for it, and the quarrel becomes one between them’ (1937: 275–76). I contend that Moore had something to do with this. Moore’s 1900s negative reviews of McTaggart’s Studies in Hegelian Cosmology attack McTaggart’s anti-realism about time and his idealism. Similarly, Moore’s 1910s critiques of Bradley package his anti-realism about time with his conception of reality. Moore attained increasingly prominent status as a new realist, and famously attacked idealism – note the title of his paper ‘The Refutation of Idealism’ (Moore 1903a). Given this, I argue his critiques promoted the quarrel that Cleugh would later describe: idealists are against time, whilst new realists are for it.

The second way Moore’s realism matters concerns the influence of Main Problems on subsequent philosophy of time. Regarding the development of (what would later become known as) B-theory, I suggest that Russell’s 1913 work on time is directly responding to Moore’s 1910–11 lectures. We know that Russell read the first ten of Moore’s (then-unpublished) lectures, for he acknowledges them in the preface to his Problems of Philosophy (1912).²⁵ Despite this public acknowledgement, in private Russell found the lectures disappointing. In a letter to Ottoline Morrell dated 1 June 1911, he wrote: ‘I am reading G. E. Moore’s lectures on Metaphysics… they don’t seem to me nearly as good as they ought to be… Moore’s intellect is not so good as it was’.²⁶ In May 1913, Russell began writing a manuscript (ultimately abandoned) now known as Theory of Knowledge. This manuscript contained a chapter, ‘On the Experience of Time’, subsequently published in The Monist (Russell 1915).²⁷ This paper can be read as partly responding to Moore, as follows.

Following Gale’s proclamation, ‘The father of the modern version of the B-Theory is Bertrand Russell’ (1968: 70), many scholars read Russell as a B-theorist.²⁸ ‘On the Experience of Time’ distinguishes between ‘physical’, objective time, comprising simultaneity, before, and after; and ‘mental’, subjective time, comprising past, present and future. As Gale (1968: 70) notes, ‘most’ B-theorists accept such a distinction. In an oft-quoted passage, Russell states, ‘In a world in which there was no experience there would be no past, present, or future, but there might well be earlier and later’ (1915: 212). I argue this Russellian view, that past, present, and future are mind-dependent, could be read as an attack on many of the claims made in the first lecture of Moore’s Main Problems: that there ‘are such things as the past, the present and the future’, that things cannot ‘be truly said to exist at all’ unless it is ‘at the time at which I am now speaking’. Perhaps Russell was unimpressed by Moore’s lectures in part because of its philosophy of time – a realism that was utterly at odds with his own. And perhaps this spurred Russell to detail his own.

Regarding the development of (what would later become known as) A-theory, I have already noted that Gale’s pioneering history of time doesn’t recognise Moore as an A-theorist, let alone as its ‘father’. However, Gale does refer to Moore’s Common Sense realism:

The obvious opening move to make when confronted with an argument for the unreality of time is to appeal to commonsense facts. G. E. Moore pointed out… it is a fact that… my breakfast yesterday preceded my lunch. (Gale 1968: 15)

Moore’s position even made it onto the opening page of Iris Murdoch’s 1970 Sovereignty of Good:

There is a two-way movement in philosophy, a movement towards the building of elaborate theories, and a move back again towards the consideration of simple and obvious facts. McTaggart says that time is unreal. Moore replies that he has just had his breakfast. Both these aspects of philosophy are necessary to it. (Murdoch 1970: 1)

Moore was the first to characterise presentism and A-theory as commonsensical, and today these positions are widely so characterised. The Stanford Encyclopedia of Philosophy ‘Time’ entry states: ‘many Common Sense ways of thinking of change seem to rely on A-theory descriptions of passage’, and presentism claims to be the ‘Common Sense view’ (Emery, Markosian, and Sullivan 2020: §§5–6). Further examples abound within the literature.²⁹ I suspect these characterisations are, ultimately, rooted in Moore. He may not be known for his metaphysics of time, but his Common Sense realism has travelled down to us nonetheless.

The final way Moore’s realism matters concerns the place of his presentism and its A-theory within the history of English-language philosophy. Let’s start with presentism. English-language philosophy blossomed from the turn of the seventeenth century. Within this tradition, relatively few thinkers have defended presentism. There are no dedicated histories of presentism but I have previously discussed whether presentism would appropriately characterise the views of early moderns John Locke, Edmund Law, Abraham Tucker, and William Hazlitt (Thomas 2018: 203; 2023b).³⁰ Scholars have also debated whether Thomas Reid is a presentist.³¹ In his mid-nineteenth century study of Reid, William Hamilton comments in passing on Reid’s pertinent remarks, and in this context seemingly advances presentism himself.³² With the exception of this fleeting comment from Hamilton, and the intriguing lines from Sidgwick quoted above, I am not aware of any other nineteenth century English-language philosopher who defends presentism. And all the attributions of presentism listed here are tentative or conjectural, based on ambiguous, often very brief remarks, regularly comprising no more than a single sentence. In contrast, the presentism of Main Problems is clear and detailed. In 1910, Moore’s lectures set out the most substantial defence of presentism ever before offered in English.

Let’s move on to A-theory. In the letter that opens this paper, dated 3 January 1909, McTaggart thanks Moore for providing criticisms ‘of my Time paper’. Given the remarks that follow, Moore had surely provided criticisms of McTaggart’s ‘The Unreality of Time’ (published in October 1908). Frustratingly, these criticisms are not extant. Yet they evidently led McTaggart to believe that Moore holds the real nature of time to be an A-series: ‘You say [the A series] is necessary for time’. This accords with my reading of Moore as an A-theorist. In his history of A-theories, Gale doesn’t list anyone as a parent; within Gale’s bibliographical lists of A-theoretic texts, the earliest given is C D Broad’s 1923 Scientific Thought.³³ I say we should push the start date of A-theory back by over a decade, to Moore’s Main Problems. Moore’s substantial presentism, and early A-theory, should accord him an vital place in the history of philosophy of time.

References

Acknowledgements  In addition to the formal referees named below, I am grateful to Tom Baldwin for informal comments on this paper; and to Antony Eagle for all his help in seeing it through.

Peer reviewers  Matyáš Moravec (Queen’s University Belfast) · Aaron Preston (Valparaiso)
Editor  Antony Eagle (Adelaide)

G E Moore’s Time Realism is © Emily Thomas 2024. This material is published under a Creative Commons license: CC BY-NC 4.0 .