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from the operation of v.arious causes (a principal one, however, being 

 the too exclusive and undue importance attached to the Aristotelian 

 logic in the schools), that some centuries had elapsed since the 

 revival of learning before the inductive method (which, by the way, 

 is nothing more than the logic which we all make use of instinctively 

 in the ordinary concerns of life) became generally applied to the in- 

 vestigation of the phenomena and laws of the material universe. But 

 a still further time elapsed, even after the publication of Lord Bacon's 

 views on the subject, before other sciences began to partake of this 

 movement ; and when they did so, it seems not possible to doubt 

 that it was the result of the impulse which the rapid growth of the 

 physical sciences had communicated to them. 



That such was the opinion of David Hume as to the influence 

 thus exercised on one class of inquiries in which he was himself 

 engaged, I have already shown. But long before Hume wrote, the 

 same impression had existed on the mind of Locke, as will be suffi- 

 ciently obvious to anyone on reading the Introductory Chapter of 

 his 'Essay on the Human Understanding/ In fact Locke had 

 originally directed his attention to Natural Philosophy and Medicine ; 

 and his researches in Moral and Intellectual Philosophy were engrafted 

 on his earlier studies. So in the case of Dr. Berkeley : his treatise on 

 * Vision ' contains the essential part of those doctrines which he after- 

 wards published in his * Treatise on the Principles of Human Know- 

 ledge ; ' and it is easy to see how, step by step, these gradually arose out 

 of his former studies of Natural Philosophy. I make no reference to 

 the modern German school of metaphysicians, and indeed am quite 

 incompetent to do so. Neither do I refer to another order of meta- 

 physicians, one of whom informs us how ideas and emotions and 

 volitions are produced by big and little vibrations of the molecules of 

 the nervous system ; while another undertakes to explain " the action 

 of material ideas in the mechanical machines of the brain." But 

 with regard to the more eminent of our English writers on 

 these subjects, and what has been called the Scotch school of 

 metaphysicians, including Reid, Adam Smith, Dugald Stewart, and 

 Brown, it may be truly asserted that the advantage which they have 

 had over the dreamy metaphysicians of former times is to be attributed 

 to their having in their mode of inquiry followed the example which 

 had been set them in the study of the physical sciences. 



