The chief reason, however, for my dwelling so long on this central and governing relation, which the philosophy of intellect bears to all other philosophy, is, that I am anxious to impress their relation strongly on your minds; not so much with a view to the importance which it may seem to give to the particular science that is to engage us together, as with a view to those other sciences in which you may already have been engaged, or which may yet await you in the course of your studies. The consideration of mind, as universally present and presiding,--at once the medium of all the knowledge which can be acquired, and the subject of all the truths of which that knowledge consists,--gives, by its own unity, a sort of unity and additional dignity to the sciences, of which their scattered experiments and observations would otherwise be unsusceptible. It is an unfortunate effect of physical inquiry, when exclusively devoted to the properties of external things, to render the mind, in our imagination, subordinate to the objects on which it is directed; the faculties are nothing, the objects every thing. The very nature of such inquiry leads us perpetually without to observe and arrange, and nothing brings us back to the observer and arranger within; or, if we do occasionally cast an inquisitive glance on the phenomena of our thought, we bring back with us what Bacon, in his strong language, calls “the smoke and tarnish of the furnace;”--the mind seems, to us, to be broken down to the littleness of the objects which it has, been habitually contemplating; and we regard the faculties that measure earth and heaven, and that add infinity to infinity, with a curiosity of no greater interest, than that with which we inquire into the angles of a crystal, or the fructification of a moss. “Ludit istis animus,” says one of the most eloquent of the ancients,--“Ludit istis animus, non proficit; et philosophiam a fastigio deducit in planum.” To rest in researches of this minute kind, indeed, if we were absolutely to REST in them, without any higher and profounder views, would truly be, as he says, to drag down philosophy from that pure eminence on which she sits, to the very dust of the plain on which we tread. To the inquirer, however, whose mind has been previously embued with this first philosophy, and who has learned to trace, in the wonders of every science, the wonders of his own intellectual frame, there is no physical research, however minute its object, which does not at once elevate the mind, and derive elevation from it. Nothing is truly humble, which can exercise faculties that are themselves sublime.