2. We here mean by _Science_, that exact, general, speculative knowledge, of which we have, throughout this work, been endeavouring to exhibit the nature and rules. Between such Science and the _practical Arts_ of life, the points of difference are sufficiently manifest. The object of Science is _Knowledge_; the object of Art are _Works_. The latter is satisfied with producing its material results; to the former, the operations of matter, whether natural or artificial, are interesting only so far as they can be embraced by intelligible principles. The End of Art is the Beginning of Science; for when it is seen _what_ is done, then comes the question _why_ it is done. Art may have fixed general rules, stated in words; but she has these merely as means to an end: to Science, the propositions which she obtains are each, in itself, a sufficient end of the effort by which it is acquired. When Art has brought forth her product, her task is finished; Science is constantly led by one step of her path to another: each proposition which she obtains impels her to go onwards to other propositions more general, more profound, more simple. Art puts elements together, without caring to know what they are, or why they coalesce. Science analyses the compound, and at every such step strives not only to perform, but to understand the analysis. Art advances in proportion as she becomes able to bring forth products more multiplied, more complex, more various; but Science, straining her eyes to penetrate more and more deeply into the nature of things, reckons her success in proportion as she sees, in all the phenomena, however {132} multiplied; complex, and varied, the results of one or two simple and general laws. 3. There are many acts which man, as well as animals, performs by the guidance of nature, without seeing or seeking the reason why he does so; as, the acts by which he balances himself in standing or moving, and those by which he judges of the form and position of the objects around him. These actions have their reason in the principles of geometry and mechanics; but of such reasons he who thus acts is unaware: he works blindly, under the impulse of an unknown principle which we call _Instinct_. When man's speculative nature seeks and finds the reasons why he should act thus or thus;--why he should stretch out his arm to prevent his falling, or assign a certain position to an object in consequence of the angles under which it is seen;--he may perform the same actions as before, but they are then done by the aid of a different faculty, which, for the sake of distinction, we may call _Insight_. Instinct is a purely active principle; it is seen in deeds alone; it has no power of looking inwards; it asks no questions; it has no tendency to discover reasons or rules; it is the opposite of Insight.