The Cow Jumped Over the Moon

THE CONTRIBUTORS’ CLUB

A PRACTICAL person the other day read over something that I ’d written for pure amusement. It was about the present having no duration, and nothing, therefore, having ever been able to happen.

‘There is a flaw in your logic,’ he said, with an interest that surprised me. 4 You make the mistake of supposing that all of an event must happen at once.’

‘How much of it does happen at once?’ I asked.

‘Only an infinitely small portion,’he replied. ‘Take a cat jumping out of the window —’

‘The cow jumped over the moon, if you like.’

‘No, let’s keep to the possible. A cat jumps through the window. Divide her — theoretically, of course — into an infinite number of infinitely thin sections — ’

‘Like a sliced sausage?’

‘Exactly. And each infinitely thin slice will pass over a given point on the window sill in that infinitely narrow portion of duration which is the present. So there is nothing logically impossible about an event’s happening at all.’

‘Pardon me,’ said I, ‘but I refuse to grant that the present is an infinitely narrow portion of duration. It is a line drawn between the past and the future. If you assume that it has even an infinitely small breadth, you assume a line having thickness — which is absurd.’

‘Who says that the present is a line?’ he retorted, beginning to show the merest trifle of impatience. ‘That’s your mistake. The present is a strip, infinitely narrow, between —’

‘Don’t go on,’ I interrupted. ‘If you make the present a strip, or stripe, instead of a line, I shall insist on dividing it, the way grammarians do the tenses. Then we’ll have a future present and a past present. Where they join will be the present present, — a mere line, again,— and the other two will be either past or future in relation to that. You will have gained nothing but a lot of words.’

‘Is there anything in this whole argument but words?’

‘You own up beaten,’ said I.

‘I don’t. But I ’ll grant your point — or line, rather. What I should have said in the first place is that our jumping cat is divided into slices having no thickness at all.’

‘Like the surface of a solid, which, having no thickness, has no existence, and yet — ’

‘You know what I mean,’ he cut me off. ‘And now you must admit that one of the slices can pass over a point on the window sill even during your line of a present.’

‘I do,’ said I.

‘There! I told you so. There is nothing like reasoning a little over these seeming paradoxes. They disappear.

‘Wait,’ I insisted. ‘I admit that a slice having no thickness could pass over the sill in the present tense. But how long would it take the cat the whole cat — to get through at that rate?’

‘Depends upon the speed,’ was the response. ‘There is no difficulty in that. As our slices are infinitely thin, an infinite number of them would go out of the window in any time you might name.’

‘No,’ I gloated. ‘Now you’re going back to your infinitely thin slices, which you’ve already had to abandon as impractical. We’re in the stage of slices having no thickness whatever. Therefore, a slice represents no part of the cat. No matter how many infinities of slices went over the sill in no matter how infinitely small a fraction of an instant, the cat herself would n’t move — she’d be hanging motionless in the air.’

‘But, he went on, — plainly floundering now and sparring for time, — ‘let us suppose that the forward half of the cat has already passed over — that is, into the future —’

‘Into the past,’ I corrected patiently. ‘The tail-end is the future of this cat, having yet to make the jump which — according to your hypothesis — has already been achieved by the head, or past end.’

‘All right. Yes, I suppose I do mean that. And let us assume that the dividing line between the two ends is — was — will be — hang it! How do you account for it? We know a cat can jump through a window, and that she does n’t do it in either the past or the future, but the now.’

‘Don’t be too certain,’I suggested. ‘Personally I’m not quite convinced that it is n’t the window that jumps through the cat — though Spinoza pretended to regard it a slip of the tongue when one of his pupils told him that he had seen a yard fly into the rooster.’

‘ You’d better let Spinoza alone,’ said my friend, with the air of one who has just been defeated, and then remembers that there was n’t anything at stake. ‘The man for you is Einstein.’

I admitted that I adored Einstein.

‘ Understand him ? ’

‘Not I. But he has deepened my blessed conviction that I don’t understand anything — not even why a billiard ball continues to roll after you have hit it with a cue.’

‘I myself can enlighten you there,’ said my friend, cheering up again — he’s really a capital fellow. ‘It rolls because of the momentum you have given it.’

‘What is momentum?’

‘ Did n’t you ever go to school ? Why, I remember the definition — substantially, that is — even yet. Momentum is the tendency of a body, once set in motion, to continue in motion at that same speed forever and in a straight line. It would, too, only for the pressure of the air, the friction of the billiard cloth, and things like that.’

‘I see. Momentum is a word representing a lot of other words. It’s the words which make the ball roll.’

‘Not at all. Momentum is a tendency, a force, a statement of how things are.’

' Then I don’t see,’ I complained, ‘that you’ve done anything but state in other terms the phenomenon which I wanted to have explained — explained, not restated. Where is this tendency located? Is there any difference between the atoms of a rolling ball and the atoms of a ball at rest?’

‘The rolling ball is warmer than the quiet one,’he ventured cautiously. ‘And the slight flattening of the ivory at the point of contact with the cloth is a bit accentuated, owing to the force with which the moving particles strike — ’

‘Look here! Do you claim it’s the heat, or the flat spot, that makes the ball move?’

‘N-no; not the heat, of course. And it could n’t be the flat spot, for any force which the particles might exert in the rear by expanding through resiliency is cancelled by the force required to compress those in front.’

‘Why not admit, then, that it is impossible for a billiard ball to roll — that it merely does it? And that momentum is simply a short way of describing its unaccountable conduct?’

My friend smiled indulgently into the open fire, and puffed twice on his cigar.

‘I see where you’re bringing up now,’ he declared after a moment. ‘Might have known. You’re going to begin to spout that old theory that there is no reality in material existence: that a cat does n’t jump through the window, because there is no cat — that it is all an illusion, imagination, a movement of brain-particles within yourself. You’re going to try to prove that I ’m not sitting here, that nobody is anywhere — that you, yourself, are a disembodied spirit and the only reality in the universe.’

‘I wish it were as simple as that,’ I smiled back. ‘Of course I’m the only being of whose existence I am certain.’

‘Better not let the Only Woman hear you say so.’

‘She has heard me say so often. And she agrees — only she insists that she is the one whose being is beyond question.’

‘Gad! And it serves you right.’

‘But don’t you see?’ I went on. ‘All these difficulties about the cat and the billiard ball, not to mention a hundred others, follow me even into the realm of illusion. It is just as impossible to understand an imaginary change as a real one; just as difficult to account for the momentum of a brain-particle as the momentum of a comet; just as far beyond the human mind to figure out how a dream-cat can act in a nonexistent present — a present which can’t even be postulated as existing without giving it breadth, which is contrary to any sensible definition; just as much of a job, in short, to deal with a dream-cat as with a tomcat.’

‘Are you happy?’ asked my friend as he rose to go.

‘Perfectly.’

‘Well, that’s the mystery that gets me. Good night. If I stay here any longer talking this way, I ’ll feel afraid of the earth giving way under my feet. I would n’t have your “tendency” for a million dollars.’

I was sorry to see him go, but pleased to think that he had been able to find no flaw in my reasoning. The trouble is — I can’t find any flaw in it myself.