Note by Dunne 
Authors Preface 
Chapter I 

A Note by J. W. Dunne

I have been asked (a considerable compliment) to say whether the changes in science and philosophy which have taken place during the last twenty years are such as would enable us to regard the events recorded in this book as logically possible. The question, I understand, is hypothetical. I am not to discuss the accuracy or inaccuracy of the story; but am merely to say whether, if true, it is in any way contrary to modern commonsense.
In 1911, when this book first was published, the popular ontology regarding `time' was that all `reality' is confined to the instant called `now', and that the `past' and the `future' are purely imaginary. This did not mean that, if you could travel into the past, you would find nothing there--it meant that there is no past to travel into.
This supposition was assailed--as everybody knows--by Einstein. He produced evidence that what one man on one planet would regard, quite correctly, as past time, another man on another planet might regard, equally correctly, as present space. Hence, if Einstein is right, the contents of time are just as `real' as the contents of space. Marie Antoinette-- body and brain--is sitting in the Trianon garden now. But what does that `now' mean? Obviously, it cannot mean the three-dimensional `now' of the ordinary, three-dimensional individual. It is a four-dimensional `now', such as would be employed by a super-mind which could perceive Marie Antoinette and you (who are reading this) as equally present to perception. The argument of relativity was that the only correct way to describe the world is in terms of this greater `now', and that three-dimensional `nows' are only subjective effects due to the peculiar positions which different people occupy in that greater world.
This four-dimensional world arrived at by relativity was declared by its expounders (in a moment of departmental enthusiasm) to be a complete world, covering all that has happened and all that will happen. Yet it was obvious that, thus limited, the conception was not up to the physicist's usual high standard of requirement. For physics is based upon experiment, that is, upon experiences of individuals in reading instruments at those individuals' single, three-dimensional `nows'. Its object is to account for the order characteristics apparent in those experiences, and one of the most important of these characteristics is that the contents of the individual's single `now' (i.e. the instrument observed) change. That is the initial experimental fact presented to the man of science--the starting point of his enquiry--his sole reason for considering the notion of `time' at all; and a physical solution which is to account for that fact has got to show how (though not `why') it is that each individual has a single `now' with changing contents. The over-hasty attempt to shut up the world in four dimensions fails in this respect. It provides each person living in that world with a three-dimensional `now' for every instant of his life, but (and this is the point) none of those `nows' could be the unique, single `now' credited to that individual at the outset. He would be left with an infinite number of `nows', all equally valid, and all equally real-seeming to him. Such a creature could not regard his experience of external events as successive; and so, by halting at four dimensions, the system denies the very thing it was devised to account for. If we rectify the omission by adding to the world the unique, single `nows' required by its various denizens, then we have it that those `nows' must travel through that world (in order that their contents may change, as required). That, of course, is to realize that the limited four-dimensional world contains space only--which accounts for why its alleged `time dimension' is, in practice, indistinguishable from space!
Again, since a physicist who is drafting a `space-time' world is obliged to start with single individual `nows' of changing content, his world is built upon those foundations, and he may not expect to find that those foundations are without significance in the resulting edifice. This significance becomes apparent as soon as it is grasped that the `nows' must travel; for the briefest examination of modern statistical physics shows that the `nows', in thus travelling, must alter the structure of the world they move in.
Clearly then, whatever the relativist's supposed restricted world of four dimensions may contain, it does not cover absolute time, for quite a lot of changes are taking place in it, both from the physicist's and the psychologist's point of view.
The theory which deals with (inter alia) the above views of the time problem is called `Serialism'; and, although it is only in its infancy, the indications are that it extends to cover the whole relation between physics, physiology, and human experience.
The theory in question demonstrates that the physicist's time can never be anything but an abstraction from real time--a particular aspect of real time--its aspect as a length moved-over by the observer. That aspect can never represent the absolute time in which events happen. Absolute time is unreachable by physical or any other analysis, no matter how many dimensions you may add to the world. Yet, according to serialism, the two aspects of the physical world exhibited as, respectively, the contents of any three-dimensional `now', and the contents of the four-dimensional field traversed by that `now', are perfectly valid aspects. Only--they are inadequate; they do not give, for anybody's purposes, a complete account of time.
But what, for readers of this book, is of more immediate interest is that, according to serialism, those two aspects of the world-- the three-dimensional and the four-dimensional--are not only aspects to be thought-of by the intellect, they must correspond to two actual outlooks on the world possessed by one-and-the-same psychological observer. That sounds an amazing assertion. `Surely,' you may object, `if I had two outlooks on the world, a greater and a smaller, I should be fully aware of the fact?' The answer is that you are, in all probability, fully aware of the act; but that, when you employ the larger outlook, you do not realise what you are doing. For the ordinary observer, habitually, confines his attention strictly to the narrower outlook provided by the special physical conditions which exist at his three-dimensional `now',--the ordinary world of waking life. But, in sleep, there is nothing at that `now' for him to observe (the brain there is dormant), and he is left then to make the best sense he can out of the larger, four-dimensional outlook which he has been ignoring. What he does make of it--pretty fair nonsense--he calls a `dream'.
This larger outlook embraces, of course, what he, when concentrating attention on the narrower view, would call his past and future life (a fact which everybody can submit to the test of experiment). So a dreamer's attention can travel to and fro in the physicist's alleged fourth-dimensional `time'.
Investigation shows that there is nothing beyond established habit to keep us, when awake, from using our larger outlooks; but every psychologist knows that a fully established habit amounts to, practically, an inhibition. Habit is quite sufficient to render us totally blind to what, otherwise, we should see. Nevertheless, habit is not absolute compulsion; and many persons, myself included, can obtain glimpses of the larger world even when awake. Also, because nothing but habit is involved, some people lapse into this sort of mind-wandering much more readily than others. They do it mostly, I think, unintentionally; at moments when attention to the narrower `now' is relaxed. So it would be perfectly rational for Miss Moberly and Miss Jourdain to perceive, waking, external scenes which had happened in their own pasts.
But the scenes which (according to our agreed-upon assumption) the two ladies saw, happened long before either of them were born. Moreover they were, according to serialism, scenes which could be observed only via the eyes and brain of some person present in the garden at the period in question, October the 5th, 1789. For either lady to see them, her attention would need to have travelled back beyond the limits of her own life and have jumped to somebody else's brain. And that, of course, would be, not only `time-travelling', but `telepathy'.
Serialism has some light to throw here. For it is able to prove very easily what every idealistic philosophy has tried to prove-- and failed. It shows that all our individual minds are merely aspects of a universal, common-to-all mind, which mind has for its four-dimensional outlook all the individual outlooks. But the real difficulty is this: The attention of the universal mind, when revisiting the `past' and observing the Trianon garden through the eyes of some person present there on October 5th, 1789--let us say, the child Marion--would constitute, one might argue, Marion's attention rather than the attentions of either Miss Moberly or Miss Jourdain, and memories of that revisiting would pertain to the universal mind as Marion rather than as anybody else. So the problem of the `telepathy' remains much the same as before. And that is the difficulty which confronts everyone who tries to explain telepathy by reference to a common-to-all mind.
A serialist, however, can see a lot of daylight here. In fact, a combination of serialism with relativity seems to me to lead straight to full telepathy. But I have a rooted distrust of easy-seeming solutions, and should prefer to study that one a great deal longer before venturing to adopt or discard it.
The foregoing is the most I have to offer from the scientific point of view. But, speaking as a layman, and, as such, permitted to indulge in pure speculation, I should like to point out one thing. There is no reason why the Trianon garden should be more subject to `ghostly' disturbances than any other of the thousand places in Europe where people have lived in a state of terror and dismay. There is a difference, it is true; but it does not lie in the happenings which took place in Versailles. It lies in the interest which those happenings arouse in our minds to-day. The tragic story of Marie Antoinette, raised, for us, by its glamour of Queenship, above the dull tale of other people's calamities, is intensely dramatic. And it is the only tale the garden possesses. We can see London for the first time without thinking of the Great Plague, but it would be impossible for any educated person to pay a first visit to the gardens of the Trianon without visualising these in relation to Marie Antoinette. Granted that absorption in that particular part of the past, anyone who is capable, when awake, of mental `time-traveling' combined with `telepathy' would be likely to see what these two ladies saw--through the eyes of any persons who walked in that garden in the year 1789. In this connection, the changes in size of the scenery as seen `then' and seen `now', suggest that the brains of the child Marion and of the very tall gardener are among the many `windows' which are available to travellers to those `times'.