Henri Bergson

The existence of life is so undisputable that it seems idle to ask what is the most general characteristic by which life is to be recognized. And yet it is necessary to ask this question, for according to the answer we give we shall conceive differently the relation of the organized to the unorganized, and also the relation of the animal to the plant, that of consciousness to cerebral activity, in short, the spring of the whole evolutionary movement.

What is most striking in a living being is that it is, as it were, a center of indetermination, and that the higher it stands in the scale of organization, the more marked is this indetermination. The plant must remain fixed to the spot where it has put down its roots; but the animal can move about. The man of science can foresee the state of a solar system at the end of a certain number of millions of years, but who would dare to predict the mental state of even the simplest organism a few moments hence?

This contrast is instructive. In the inorganic world, the individual object counts for little; the individual is only an accident, and if it appears to persist as an individual, it is because it crystallizes, so to speak, a certain law of nature. But in the organized world the individual counts for much more. Not, of course, that it can escape the necessity which governs matter; but this necessity manifests itself here rather by the tendency of every living being to adapt itself to circumstances and to solve in its own way the problem of existence set before it.

Life transcends both mechanism and finality by its very definition. The essence of life is in the movement by which life is transmitted; it is this continuity of movement, it is this heredity, that is the life of life.

Now, heredity, so far from implying a tendency to repeat, implies on the contrary a progress, a growth, an increasing complexity. The living being grows old. This is of its very essence. For to live means to grow old. More precisely: the organism begins by being a simple cell; it becomes, by successive divisions and differentiations, a body with billions of cells; but all these cells have a common origin, and we may say that they have continued to live the same life, only they have shared it among them.

When I consider the living being in this way—that is to say, as a current of life flowing through generations of individuals—I find that evolution consists, above all, in a progress, that this progress is definite in direction, although not always apparent, and that the direction of this progress is toward an increasing complexity of structure united with an increasing perfection of function.

But here we must be on our guard against a confusion that has vitiated many theories. When we speak of progress and of evolution, we must not be the victims of a confusion between the true evolution, which is a change of form, and that pseudo-evolution which is nothing but a growth of size, or complication of what was given.

The élan vital, or vital impetus, which I regard as the deep cause of evolution, appears to me as a finite principle, which has found in organized matter, and particularly in the nervous system of animals, the means of giving itself ever new and more and more complex forms, but which is exhausted in the very effort by which it manifests itself.

The impetus of life consists in a need of creation. It cannot create absolutely, because it encounters matter, that is to say, movement inverted. On this matter it has a hold, and it endeavors to introduce into it the largest possible amount of indetermination and liberty.

The animal world and the plant world, though they have both issued from the same source, represent two different directions of the development of life. In the plant, consciousness falls asleep; in the animal, it awakens. But in both it is present, for both live; and everywhere that there is life there is consciousness lying dormant and liable to wake up.

Regarded in this light, consciousness appears as the motive principle of evolution. Conscious life is really like a current passing from germ to germ through the developed organism which serves as an intermediary. Everything happens as if consciousness, originally imprisoned in matter, endeavored to free itself and succeeded, step by step, in developing more and more powerful instruments of action—more and more effective bodies.

The evolution of life really consists in the elaboration of forms ever new and ever more complex. But complexification for the sake of complexification would be absurd. There is complexification only because there is something to be gained by it. Now what is gained is a greater independence, a more complete liberty of action.

This is why, among the thousand and one paths which life might have taken, it is easy to see that the chosen path is that which leads to the human species. Not that man is the goal toward which the whole of life is tending. He is simply the form in which, at a given moment, the fundamental tendency of life finds its most complete expression.

And this tendency is nothing else than the need to act freely. Freedom of action means possibility of choice, and possibility of choice can come only through intelligence.