68. Notwithstanding the importance justly attached to the refutation of the German philosopher's errors, I do not deem it necessary to combat his doctrines step by step; this system of refutation labors under the serious objection that it gives little satisfaction to the reader, who seems to see one edifice torn down, but not replaced by another. I consider it more useful carefully to examine questions as they arise in the order of their subjects, to establish my opinion as best I can, and there to refute Kant's errors as I find them obstructing the march of truth. It is ordinarily very easy to say what a thing is not; but it is not so easy to say what it is; and it is not proper that the advocates of sound doctrine should be charged with impugning false doctrines, and not caring to expose their own. We believe that in these matters sound philosophy may be presented to the light of the day struggling against error, and that it ought not to rest satisfied with being the instrument of war to overthrow its adversary, but that it should aspire to found a noble and enduring edifice upon the very site the other occupied. The minds of men are not satisfied with simple refutations; they desire to have a doctrine substituted in the place of the one impugned. Whoever impugns, denies; and the understanding is not satisfied with negations; it wants affirmation, for it cannot live without positive truth. We have permitted ourselves this brief digression, which is indeed far from being useless; for at the sight of the transcendency of the German philosopher's errors I have recollected the necessity of careful, assiduous, and profound labor to oppose this deluge of errors which threatens to inundate the whole field of truth; and we could not do less than insist upon this point, and observe that it is not enough to tear down, but that it is also necessary to build up. Refutations will soon come; but let positive doctrines abound. It is not enough to cover the long line of frontiers where error makes its attacks, with light and active troops which may fall upon the enemy; it is necessary to found colonies, foci of cultivation and civilization, who will defend the country, at the same time that they make it flourish and prosper. CHAPTER X. SENSIBLE INTUITION. 69. Intuition, properly so called, consists in the act of the soul by which it perceives an object that effects it: this the signification of the Latin word derived from the verb _intueri_, to see a thing which is present, indicates.