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 and Transcendentalism—extremes that virtually meet—which alone is open to him during his sojourn on this “isthmus of a middle state.”

But we must be more definite in our account of this stage in the Cartesian revolution. For this purpose three central ideas of the new Scottish Philosophy of Sir William Hamilton, selected from a host of others, presented in these Notes and Dissertations, which, with their text, embrace problems in the whole circle of the sciences of metaphysics, logic, and morals, may be employed as the basis of the remaining part of this Essay.

I. The theory of Common Sense, regarded as at once supporting and limiting human knowledge, which is developed in the first and most extended of the dissertations, and suggested in various of the footnotes throughout the work.

II. The theory of immediate or conscious external Perception, expounded in the four dissertations on “presentative and representative knowledge;” on “the various theories of external perception;” on “the distinction of the primary and secondary qualities of matter;” and on “perception proper and sensation proper.” It is also referred to in the footnotes, especially those on the “Inquiry,” and the second of the “Essays” on the intellectual powers.

III. The germs or scintillations of a theory of Freewill, or responsible agency, which are contained in the footnotes on Reid’s essay on “the Liberty of moral agents.”