judge the body, nor even occupy my thought with any matter whatever.  It is said in the schools, that the essence of a being is that from which flow all the properties of that being.  Now then, it is evident that all the properties of bodies or of substances of which we have ideas, are due to the motion which alone informs us of their existence, and gives us the first conceptions of it.  I can not be informed or assured of my own existence but by the motions which I experience within myself.  I am compelled to conclude that motion is as essential to matter as its extension, and that it can not be conceived of without it.  If one persists in caviling about the evidences which prove to us that motion is an essential property of matter, he must at least acknowledge that substances which seemed dead or deprived of all energy, take motion of themselves as soon as they are brought within the proper distance to act upon each other.  Pyrophorus, when enclosed in a bottle or deprived of contact with the air, can not take fire by itself, but it burns as soon as exposed to the air.  Flour and water cause fermentation as soon as they are mixed.  Thus dead substances engender motion of themselves.  Matter has then the power to move itself, and nature, in order to act, does not need a motor whose essence would hinder its activity.

XLII.—­THE EXISTENCE OF MAN DOES NOT PROVE THAT OF GOD.

Whence comes man?  What is his origin?  Is he the result of the fortuitous meeting of atoms?  Was the first man formed of the dust of the earth?  I do not know!  Man appears to me to be a production of nature like all others she embraces.  I should be just as much embarrassed to tell you whence came the first stones, the first trees, the first elephants, the first ants, the first acorns, as to explain the origin of the human species.  Recognize, we are told, the hand of God, of an infinitely intelligent and powerful workman, in a work so wonderful as the human machine.  I would admit without question that the human machine appears to me surprising; but since man exists in nature, I do not believe it right to say that his formation is beyond the forces of nature.  I will add, that I could conceive far less of the formation of the human machine, when to explain it to me they tell me that a pure spirit, who has neither eyes, nor feet, nor hands, nor head, nor lungs, nor mouth, nor breath, has made man by taking a little dust and blowing upon it.  The savage inhabitants of Paraguay pretend to be descended from the moon, and appear to us as simpletons; the theologians of Europe pretend to be descended from a pure spirit.  Is this pretension more sensible?