That the name "Transcendentalism" was given, a century ago, to a method in philosophy opposed to the theory of Locke--that all knowledge comes from the senses,--is more widely known than the fact that what this method affirmed or involved is of profound import for all generations. It emphasized Mind as a formative force behind all definable contents or acts of consciousness--as that which makes it possible to speak of anything as _known_. It recognized, as primal condition of knowing, the transmutation of sense-impressions by original laws of mind, whose constructive power is not to be explained or measured by the data of sensation; just as they use the eye or ear to transform unknown spatial notions into the obviously human conceptions which we call color and sound. All this the Lockian system overlooked--a very serious omission, as regards both science and common-sense. And again, in the same article--that on "Transcendentalism," first printed in the _Radical Review_ for November, 1877, and afterwards included in the volume of "Lectures, Sermons, and Essays": What we conceive these schools to have misprized is the living substance and function of mind itself, conscious of its own energy, productive of its own processes, active even in receiving, giving its own construction to its incomes from the unknown through sense, thus involved in those very contents of time and space which, as historical antecedents, _appear_ to create it; mind is obviously the exponent of forces more spontaneous and original than any special product of its own experience. Behind all these products must be that substance in and through which they are produced. And again, for we cannot be too explicit on this point: It is certain that knowledge involves not only a sense of union with the nature of that which we know, but a real participation of the knowing faculty therein. When, therefore, I have learned to conceive truths, principles, ideas, or aims which transcend life-times and own no physical limits to their endurance, the aforesaid law of mind associates me with their immortal nature. And this is the indubitable perception or intuition of permanent mind which no experience of impermanence can nullify and no Nirvana excludes.