Page:Ferrier's Works Volume 1 - Institutes of Metaphysic (1875 ed.).djvu/57

Rh no man was ever one whit the wiser, have been written on this threadbare theme. The following single canon is quite sufficient for all the purpose of a reasoned philosophy. The canon of all philosophy: "Affirm nothing except what is enforced by reason as a necessary truth—that is, as a truth the supposed reversal of which would involve a contradiction; and deny nothing, unless its affirmation involves a contradiction—that is, contradicts some necessary truth or law of reason." Let this rule be strictly adhered to, and all will go on well in philosophy. Its importance, of course, consists, not in its being stated, but in its being practised.

§ 35. With regard to the particular scheme, or Institute of metaphysics, now submitted to the public, and in which these general views are endeavoured to be carried into effect, this, at the outset, may be premised, that, while it cannot disclaim its pretensions to be both true and reasoned, without arrogating to itself a modesty for which it would get no credit,—still it desires to rest its claims to consideration rather on the circumstance that it is a system of demonstration, than on the circumstance that it is a system of truth. If it is truer than other systems, it is so only because it is demonstratively truer; and if they are falser than it, this is only because they are