To this you will be ready to answer “forces”; and after a little consideration you will see that that is no answer at all unless you tell what force is. What is force, and how does it cause substance to move? Force is not time; we cannot think of time as causing motion. Force is not space; we cannot think of space as causing motion. If force is substance and causes motion, then substance moves itself; and if force is not substance, then it is nothing, or empty space, and empty space cannot act on substance so as to cause it to move. It is all very well for scientists to write of atoms as being “electrons” or ultimate units of force; but these electrons are either substance or they are not; and if they are not substance they are nothing but empty space, and in that case there is no substance, no existence, no consciousness, no anything. Either force is substance, or it is something in substance; and if it is something in substance which is not substance, what is it? And how can that which has no substance act on substance so as to cause motion? Force is not motion, for it is the cause of motion and the effect cannot be its own cause. Let me now try to give you a definition of force. Force is pressure of substance against substance. Try to exert force upon anything in any other way than by pressing substance against it; can you do it? Try to cause a body to move in any other way than by pressing something against it; can you do it? Try to conceive of force as being exerted upon any body without pressing anything against it; try to conceive of force as crossing a complete vacuum where is no substance of any kind. Force is pressure of substance; that it can be anything else is not thinkable. And this brings us to the consideration of what is loosely spoken of as “attraction.” It is stated that all solid bodies “attract” each other, and that every body in the universe attracts every other body; but those who make these assertions do not tell us how the attraction is accomplished. If bodies “attract” each other, then they exert force upon each other; and if they exert force upon each other they must cause pressure upon each other; for how can a body exert force upon another except by causing pressure upon it? If “attraction” is an unsubstantial thing, then it cannot affect substance, or cause motion; if it is an unsubstantial thing, then it is empty space; for where there is no substance there is only empty space. Can you think of an “attraction” crossing an empty space? What would it be like, and how would it get across? Can you think of a “vibration” as crossing an empty space? How would it be transmitted where there was nothing to vibrate? Can you think of a force as crossing an empty space? What would be the shape, size and general appearance of a force apart from substance? By considering all these points we see that what we know as force is simply pressure of substance; or, one portion of