All the most important occasions of our lives are capable of being subjected at pleasure to a decision, as nearly as possible, perfectly voluntary.
Still it remains true that, when the understanding clearly perceives rectitude, propriety and eligibility to belong to a certain conduct, and so long as it has that perception, that conduct will infallibly be adopted. A perception of truth will inevitably be produced by a clear evidence brought home to the understanding, and the constancy of the perception will be proportioned to the apprehended value of the thing perceived. Reason therefore and conviction still appear to be the proper instrument, and the sufficient instrument for regulating the actions of mankind.
Having sufficiently established the principle that in all cases of volition we act, not from impulse, but opinion, there is a further obstacle to be removed before this reasoning can be usefully applied to the subject of political melioration. It may be objected, by a person who should admit the force of the above arguments, "that little was gained by this exposition to the cause it was intended to promote. Whether or no the actions of men frequently arise, as some authors have asserted, from immediate impression, it cannot however be denied that the perturbations of sense frequently seduce the judgement, and that the ideas and temporary notions they produce are too strong for any force that can be brought against them. But, what man is now in this respect he will always to a certain degree remain. He will always have senses, and, in spite of all the attempts which can be made to mortify them, their pleasures will always be accompanied with irritation and allurement. Hence it appears that all ideas of vast and extraordinary improvement in man are visionary, that he will always remain in some degree the dupe of illusion, and that reason, and absolute, impartial truth, can never hope to possess him entire."