stinct of possession causes us to impute all such to ourselves—until increasing exactitude teaches us distrust.
VI.
Now of what do ideas consist? They consist, apparently, of molecular motion. An idea, in short, is a mode of motion; another form of that fundamental, seemingly protean thing.
But to see this we must first be sure just what we mean by an idea. Now we mean in ordinary parlance by an idea a conscious pulse of thought. A mere reflex action we do not associate with any idea. We even speak often of having acted from impulse as opposed to having acted from thought, and hold ourselves largely irresponsible in consequence. Now all such unconscious brain action, whether it be so-called reflex action, or so-called instinct or impulse, there is, in the present state of our knowledge, little difficulty in conceiving to be a mere mode of motion from one end of the chain to the other. Suppose, for example, I am walking along the street, and an inadvertent gnat runs full tilt into my eye. The eye instantly
