fitable study of it, and give to the reader a clear per ception of its excellencies and defects. The second Not having part arose naturally out of the first. been originally contemplated, some slight repetitions of sentiment occur, which yet may not be unpleasing or useless to the reader. Brought up in a school in which Locke was the object of traditional veneration,-a veneration heightened and justified by reading, reflection, and experience,-I have seen with mingled astonishment and pain the attempts recently made to depose the master from his seat of honour, among those from whom better things were to be expected. But it is one thing to be convinced of the futility of the common objections to Locke's philosophy, of the ignorance in which they originate, and of the injustice of the insinuations against its character and tendency-another to display that futility, that ignorance, that injustice before the eyes of an impartial inquirer by an elaborate picture of the condition of mental and moral science before and about his time, and a truthful representation of its progress since. Learned men, as well as others, are oftentimes hard to be convinced of the falsehood of an opinion once embraced by them; "nor will they yield,” says Lardner, "till they are overwhelmed by a heap of reasons." They In addition to the observance of the excellent rules laid down by Locke for remedying the imperfection and abuse of words,-first, that words should be applied, as near as may be, to such ideas as common use has annexed them to; secondly, that they should be made, when doubtful or obscure, as clear as possible by explanation or definition, that is, by enumerating, in the case of terms significant of complex ideas, the several simple ones which enter into the complexity; and thirdly, that there should be constancy in adherence to the same meaning ;-writers touching on the history of metaphysics should also observe a fourth rule, namely, that of "faithful quotation." should never attempt to give the opinions of authors whom they criticize and controvert in words other than those which the authors themselves have used. Writers and thinkers worthy of attention express their notions in language deemed by them the fittest; a language not to be changed with advantage to their sentiments, except in so far as they have themselves supplied correction. Mr. Dugald Stewart, like most other writers on the mind, in his 'Dissertation on the Progress of Metaphysical Philosophy,' is very defective in this respect. To that dissertation I must acknowledge myself indebted for opening many paths of interesting inquiry, though the result of inquiry has led me, for the most part, to conclusions very different from my guide's. In a work of this nature, surveying so wide and difficult a field, no doubt errors will be detected; some oversight of matters worthy of attention, some instances of bad reasoning, and of that laxity of phrase against which it is so difficult to guard. Such errors I shall rejoice to see corrected, being anxious only for the fullest investigation of the subject, for the advancement of mental and moral science. My wish is to be one of those combatants whom Locke describes " as a champion for knowledge, truth, and peace; not a slave to vainglory, ambition, or a party." "Rational metaphysics," to translate a passage of D'Alembert in the admirable preliminary discourse to the Encyclopédie,' where he speaks of Locke as the Newton of the mind, "like experimental physics, can only consist in gathering with care all the facts, reducing them to a body, explaining some by others, and distinguishing those which ought to hold the first rank, to serve as the common basis." Wildwood, Hampstead, May, 1855. E. T. CONTENTS. PAGE Statement of the Design and Plan of the Work. Modern Opinions concerning Locke, Stewart, Cousin, Rémusat, Account of the commencement of the Scotch School of Me- 57 Hobbes, Clarke, and Locke defended against Stewart, and Hume's infallible relations examined Certainty in connection with Propositions founded on uniform |