329. The instinctive faith in human authority, of which we have just treated, is a fact attested by experience, and one which no philosopher has presumed to call in doubt. This faith, duly directed by reason, constitutes one criterion of truth. The errors to which it may sometimes lead are inherent in human weakness, and are amply compensated for by the advantages derived from it by society and individuals.
A celebrated writer undertook to include all criteria in that of human authority, resolutely affirming "common consent, _sensus communis_, to be to us the only seal of truth."[33] His system, as strange as erroneous, in which words as unlike as _sensus_ and _consensus_ are confounded, is defended with that eloquent exaggeration characteristic of its eminent author; but profound philosophy does not always accompany eloquence. The sad fate of this genius, as brilliant as erring, shows the results of such a doctrine; it opens an abyss which swallows up all truth, and the author himself was the first to fall into it. To appeal to the authority of others in all things, and for all things, is to despoil the individual of every criterion, to annihilate them all, not excepting the very one he attempts to establish. It is inconceivable how such a system could have found favor with so gifted an intellect. We feel, when reading the eloquent pages of its development, an undefinable pain to see such brilliant passages squandered on the repetition of all the common-places of skepticism, ending in a most glaring paradox, and the least philosophical system imaginable.
[33] Lamennais, _Essai sur l'Indifference en Matière de Religion_. T. 2, C. 13.
Lamennais calls common sense the only criterion; nevertheless, we have only to glance at the others to be convinced that this new criterion is sterile, and could not produce them.
330. The testimony of consciousness, in the first place, cannot rest in any sense upon the authority of others. Formed as it is by a series of acts intimately present to our own mind, and, as without it, it is not possible for us even to conceive individual thought, it must evidently exist prior to the application of any criterion, since no criterion is possible to him who does not think.