Like all true doctrines, this of the practical nature of the theoretical error, which at first sight seems most strange (especially to professed philosophers), is yet found to be constantly confirmed in ordinary thought. For all know and all continually repeat that (immoderate) passions and (illegitimate) interests lead insidiously into error, that we err, to be quick and finish or to obtain for ourselves undeserved repose, that we err by acquiescence in old ideas, that is to say, in order not to allow ourselves to be disturbed in our repose that has been unduly prolonged, and so on. We do not mention those cases in which it is a question of solemn and evident lies, the brazen-faced manifestation of interests openly illegitimate. Let us limit ourselves to the modest forms of error, to the venial sins, because if these be proved to be the result of will, by so much the more will this be proved of the shameless forms, the deadly sins. It is also said that we err in _deafening_ ourselves and others with words, with the verse that sounds and does not create, with the brush that charms but does not express, with the formulæ that seem to contain a thought but contain the void. In this way we come to recognize that will has been rendered possible, owing to the communication being a practical fact, of which a bad use can be made by means of a volitional act. For the rest, if this were not so, what guarantee would truth ever possess? If it were possible to err even once in perfect good faith and that the mind should confuse true and false, embracing the false as true, how could we any longer distinguish the one from the other? Thought would be radically corrupt, whereas it is incorrupt and incorruptible. It is vain, therefore, to except the existence or the possibility of errors of good faith, because truth alone is of good faith, and error is always in a greater or less or least degree, of bad faith. Were this not so, it would be incorrigible, whereas it is by definition corrigible. Consequently, the last attempt to differentiate intention from volition fails, since it posits an intention that is frustrated in the volition, as the effect of a theoretical error, a good intention that becomes, through no fault of its own, a bad volition. The intention, being volition, takes possession of the whole volitional man, causing the intellect to be attentive and indefatigable in the search for truth, the soul ready to accept it, whatever it be, pure of every passion that is not the passion for truth itself, and eliminates the possibility, or assumes the responsibility of error.