maintain that such are the tendencies of the two opposite institutions, but that such tendencies may be neutralised by counteracting causes. And yet there are thousands of educated men who call such reasoning as this arguing from experience, and are now anxious to make the tremendous experiment of an Irish poor law on the English model in reliance on what they call the experience of England. [A] This Lecture was delivered in March, 1847. When we direct our attention to the workings of our own minds, that is to say, when we search for premises by means of consciousness instead of by means of observation, our powers of trying experiments are much greater. To a considerable degree we command our own faculties, and though there are few, perhaps none, which we can use separately, we can at will exercise one more vigorously than the others. We can call, for instance, into peculiar activity, the judgment, the memory, or the imagination, and note the differences in our mental condition as the one faculty or the other is more active. And this is an experiment. Over our mental sensations we have less power. We cannot at will feel angry, or envious, or frightened. But we can sometimes, though rarely, put ourselves really into situations by which certain emotions will be excited. And when, as is usually the case, this is impossible or objectionable, we can fancy ourselves in such situations. The first is an actual experiment. We can approach the brink of an unprotected precipice and look down. We can interpose between our bodies and that brink a low parapet, and look over it. And if we find that our emotions in the two cases differ,--that though there is no real danger in either case, though in both our judgment equally tells us that we are safe, yet that the apparent danger in the one produces fear, while we feel secure in the other,--we infer that the imagination can excite fear for which the judgment affirms that there is no adequate cause. The second is the resemblance of an experiment, and when tried by a person with the vivid imagination of Shakspeare or Homer may almost serve for one. But with ordinary minds it is a most fallacious expedient. Few men when they picture themselves in an imaginary situation take into account all the incidents necessary to that situation. And those which they neglect may be among the most important. Having explained the distinction between a science and an art, and the chief differences between the arts and sciences which consider as their principal subject the laws of matter, and those whose principal subject is mind, I now come to one of the practical questions in which this long preface will I hope be found useful, namely, whether Political Economy be a mental or a physical study.