The doctrine I have just laid down is indeed obscure; but at least it suggests a meaning and there is nothing in it repugnant to reason or experience; can we say as much of materialism?  Is it not plain that if motion is essential to matter it would be inseparable from it, it would always be present in it in the same degree, always present in every particle of matter, always the same in each particle of matter, it would not be capable of transmission, it could neither increase nor diminish, nor could we ever conceive of matter at rest.  When you tell me that motion is not essential to matter but necessary to it, you try to cheat me with words which would be easier to refute if there was a little more sense in them.  For either the motion of matter arises from the matter itself and is therefore essential to it; or it arises from an external cause and is not necessary to the matter, because the motive cause acts upon it; we have got back to our original difficulty.

The chief source of human error is to be found in general and abstract ideas; the jargon of metaphysics has never led to the discovery of any single truth, and it has filled philosophy with absurdities of which we are ashamed as soon as we strip them of their long words.  Tell me, my friend, when they talk to you of a blind force diffused throughout nature, do they present any real idea to your mind?  They think they are saying something by these vague expressions—­universal force, essential motion—­but they are saying nothing at all.  The idea of motion is nothing more than the idea of transference from place to place; there is no motion without direction; for no individual can move all ways at once.  In what direction then does matter move of necessity?  Has the whole body of matter a uniform motion, or has each atom its own motion?  According to the first idea the whole universe must form a solid and indivisible mass; according to the second it can only form a diffused and incoherent fluid, which would make the union of any two atoms impossible.  What direction shall be taken by this motion common to all matter?  Shall it be in a straight line, in a circle, or from above downwards, to the right or to the left?  If each molecule has its own direction, what are the causes of all these directions and all these differences?  If every molecule or atom only revolved on its own axis, nothing would ever leave its place and there would be no transmitted motion, and even then this circular movement would require to follow some direction.  To set matter in motion by an abstraction is to utter words without meaning, and to attribute to matter a given direction is to assume a determining cause.  The more examples I take, the more causes I have to explain, without ever finding a common agent which controls them.  Far from being able to picture to myself an entire absence of order in the fortuitous concurrence of elements, I cannot even imagine such a strife, and the chaos of the universe is less conceivable to me than its harmony.  I can understand that the mechanism of the universe may not be intelligible to the human mind, but when a man sets to work to explain it, he must say what men can understand.