from thence that each science receives for him its most pervading illumination. There all his knowledge tends towards the organized unity—the sophia of the old Greek—to which our understandings can only make an approach; and, as regards which, man assumes his highest function when it is the object of his love and aspiration, according to the original eloquent meaning of the word philosophy.
It is as much for the sake of this illumination, as for the purposes of defence, that we need to foster those habits which send us in quest of the First Principles of metaphysics. Nature is usually sufficiently strong to defend, for all the uses of life, those portions of knowledge which the powerful original motives of human activity require to be converted into practice, and she can always silence, by means of action, the objections of the few sceptical adventurers who seek to find their way behind the scenes, and ingeniously contrive literally to lose themselves in the attempt. “All sceptical reasoning,” says Sir James Mackintosh, “is merely blowing up the ship, where you and your enemy go into the air together.” But the speculative consistency and completeness of those sections of knowledge, which form the various sciences, is materially diminished, and the sciences themselves must inevitably undergo a process of gradual deterioration, if human thought is not sometimes turned towards those remote outworks, whence so commanding a view may be gained of what is knowable, in contrast with what cannot be known. If the comprehensiveness of the knowledge that is possessed by the students of the
