What is liberty? What must we understand by this word? Beware of the answer you are going to give. Every definition, in the strict sense of the term, will imply the determinist thesis in advance, since, under pain of going round in a circle, it will be bound to express liberty as a function of what it is not. Either psychological liberty is an illusive appearance, or, if it is real, we can only grasp it by intuition, not by analysis, in the light of an immediate feeling. For a reality is verified, not constructed; and we are now or never in one of those situations where the philosopher's task is to create some new concept, instead of abiding by a combination of previous elements.

Man is free, says common-sense, in so far as his action depends only on himself. "We are free," says Mr Bergson, ("Essay on the Immediate Data of Consciousness", page 131.) "when our acts proceed from our entire personality, when they express it, when they exhibit that indefinable resemblance to it which we find occasionally between the artist and his work." That is all we need seek; two conceptions which are equivalent to each other, two concordant formulae. It is true that this amounts to determining the free act by its very originality, in the etymological sense of the word: which is at bottom only another way of declaring it incommensurable with every concept, and reluctant to be confined by any definition. But, after all, is not that the only true immediate fact?

That our spiritual life is genuine action, capable of independence, initiative, and irreducible novelty, not mere result produced from outside, not simple extension of external mechanism, that it is so much ours as to constitute every moment, for him who can see, an essentially incomparable and new invention, is exactly what represents for us the name of liberty. Understood thus, and decidedly it is like this that we must understand it, liberty is a profound thing: we seek it only in those moments of high and solemn choice which come into our life, not in the petty familiar actions which their very insignificance submits to all surrounding influences, to every wandering breeze. Liberty is rare; many live and die and have never known it. Liberty is a thing which contains an infinite number of degrees and shades; it is measured by our capacity for the inner life. Liberty is a thing which goes on in us unceasingly: our liberty is potential rather than actual. And lastly, it is a thing of duration, not of space and number, not the work of moments or decrees. The free act is the act which has been long in preparing, the act which is heavy with our whole history, and falls like a ripe fruit from our past life.

But how are we to establish positive verification of these views? How are we to do away with the danger of illusion? The proof will in this case result from a criticism of adverse theories, along with direct observation of psychological reality freed from the deceptive forms which warp the common perception of it. And it will here be an easy task to resume Mr Bergson's reasoning in a few words.

The first obstacle which confronts affirmation of our liberty comes from physical determinism. Positive science, we are told, presents the universe to us as an immense homogeneous transformation, maintaining an exact equivalence between departure and arrival. How can we possibly have after that the genuine creation which we require in the act we call free?

The answer is that the universality of the mechanism is at bottom only a hypothesis which is still awaiting demonstration. On the one hand it includes the parallelist conception which we have recognised as effete. And on the other it is plain that it is not self-sufficient. At least it requires that somewhere or other there should be a principle of position giving once for all what will afterwards be maintained. In actual fact, the course of phenomena displays three tendencies: a tendency to conservation, beyond question; but also a tendency to collapse, as in the diminution of energy; and a tendency to progress, as in biological evolution. To make conservation the sole law of matter implies an arbitrary decree, denoting only those aspects of reality which will count for anything. By what right do we thus exclude, with vital effort, even the feeling of liberty which in us is so vigorous?

We might say, it is true, that our spiritual life, if it is not a simple extension of external mechanism, yet proceeds according to an internal mechanism equally severe, but of a different order. This would bring us to the hypothesis of a kind of psychological mechanism; and in many respects this seems to be the common-sense hypothesis. I need not dwell upon it, after the numerous criticisms already made. Inner reality—which does not admit number—is not a sequence of distinct terms, allowing a disconnected waste of absolute causality.

And the mechanism of which we dream has no true sense—for, after all, it has a sense—except in relation to the superficial phenomena which take place in our dead rind, in relation to the automaton which we are in daily life. I am ready to admit that it explains our common actions, but here it is our profound consciousness which is in question, not the play of our materialised habits.

Without insisting, then, too strongly on this mongrel conception, let us pass to the direct examination of inner psychological reality. Everything is ready for the conclusion. Our duration, which is continually accumulating itself, and always introducing some irreducible new factor, prevents any kind of state, even if superficially identical, from repeating itself in depth. "We shall never again have the soul we had this evening." Each of our moments remains essentially unique. It is something new added to the surviving past; not only new, but unable to be foreseen.

For how can we speak of foresight which is not simple conjecture, how can we conceive an absolute extrinsic determination, when the act in birth only makes one with the finished sum of its conditions, when these conditions are complete only on the threshold of the action beginning, including the fresh and irreducible contribution added by its very date in our history? We can only explain afterwards, we can only foresee when it is too late, in retrospect, when the accomplished action has fallen into the plan of matter.