Having called attention to this view, and commended it to the consideration of my readers, I proceed to another which should not have been left to be touched upon only in a final chapter, and which, indeed, seems to require a book to itself—I refer to the origin and nature of the feelings, which those who accept volition as having had a large share in organic modification must admit to have had a no less large share in the formation of volition. Volition grows out of ideas, ideas from feelings. What, then, is feeling, and the subsequent mental images or ideas? The image of a stone formed in our minds is no representation of the object which has given rise to it. Not only, as has been often remarked, is there no resemblance between the particular thought and the particular thing, but thoughts and things generally are too unlike to be compared. An idea of a stone may be like an idea of another stone, or two stones may be like one another; but an idea of a stone is not like a stone; it cannot be thrown at anything, it occupies no room in space, has no specific gravity, and when we come to know more about stones, we find our ideas concerning them to be but rude, epitomised, and highly conventional renderings of the actual facts, mere hieroglyphics, in fact, or, as it were, counters or bank-notes, which serve to express and to convey commodities with which they have no pretence of analogy. Indeed we daily find that, as the range of our perceptions becomes enlarged either by invention of new appliances or after use of old ones, we change our ideas though we have no reason to think that the thing about which we are thinking has changed. In the case of a stone, for instance, the rude, unassisted, uneducated senses see it as above all things motionless, whereas assisted and trained ideas concerning it represent motion as its most essential characteristic; but the stone has not changed. So, again, the uneducated idea represents it as above all things mindless, and is as little able to see mind in connection with it as it lately was to see motion; it will be no greater change of opinion than we have most of us undergone already if we come presently to see it as no less full of elementary mind than of elementary motion, but the stone will not have changed.