This is by far the more profound and important of the two inquiries, although the maxim which inculcates it has been usually assumed by moral declaimers as a text from which they might expatiate on the other theme—the weakness, namely, and the fallibility of man.
8. We have, then, studiously to examine ourselves, with the view of ascertaining what thought is, and how it is distinguished from sensation. It is a common saying, both in ordinary discourse and in metaphysical disquisition, that thought is free and active, that sensation is necessitated and passive; in other words, that our mental freedom and activity consist in thought, while our mental receptivity or passivity consist in sensation. The mind is free and active when it thinks: it is compelled and passive when it feels. This statement is perfectly correct and true, but it does not carry us far. These words "free and active" throw no light whatever on the nature of thought, until after we have discovered what thought is; and then, but not till then, do we see that they are proper epithets to apply to it. To ascertain, then, what thought is, we are thrown entirely upon our own reflection. I must confess that I have found in books very little help towards clearing up the mystery. Books, indeed, lend us only the feeblest assistance. They tell us, as I have said, that thought is free and active; but there they leave us, to find out the meaning of these words for
