If there is one department of knowledge more than another in which a contemptuous disregard of the meditations and theories of distant periods and nations is misplaced, it is in the philosophy of man,--which can have no adequate breadth of basis till it reposes on the consciousness and covers the mental experience of the universal race; and to construct which out of purely personal materials, is like attempting to lay down the curves and finish the theory of terrestrial magnetism on the strength of a few closet experiments. No man, however large-thoughted and composite his mind, can accept of _himself_ as the type of universal human nature. It will even be a great and rare endowment, if, with every aid of exact learning and unwearying patience, he is able to penetrate the atmosphere of others' understanding, and to observe the forms and colors which the objects of contemplation assume, when beheld through this peculiar medium. Simply to avail one's self of the experience of mankind, and know what it has really been, demands no little scope of imagination and versatility of intellectual sympathy. When these qualities are so deficient in a thinker that he cannot well achieve this knowledge, it is a great misfortune to his philosophy; when the want is such that he does not even desire it, it amounts to an absolute disqualification. Without, therefore, pledging ourselves to the eclectic principles which prevail in the present school of philosophy in France, we must beware of the intolerant dogmatism of Bentham in England, sanctioned, as we have seen, by one of the masters of the antagonist metaphysics in Germany. Indeed, it will be a chief purpose of all my lectures to enable you to profit by the light of other minds; in every province of the vast region which we shall explore together, to indicate the paths which they have traversed before, nor ever to turn away from their points of discovery, without raising some rude monument at least of honest and commemorative praise. To introduce you to the works, to interpret the difficulties, to do honor to the labors, to review the opinions, of the great masters of speculative thought in every age and in many lands, will be an indispensable portion of my duty;--a task most arduous indeed, but than which none can be more grateful to one who loves to trace, through all their affinities, the indestructible types of truth and beauty in the human mind; and to mark the natural laws, connecting together the most opposite continents and climes of thought, as parts, successively colonized and cultivated, of one great intellectual world. But in addition to the study of the several classes of psychological and moral doctrine as they present themselves in the _order of science_, it will be important to spread out the literature of philosophy before us in the _order of time_; to gain an insight into the natural development of successive modes of thought on