XXVII. Independently of these external impediments, there exists a kind of internal anarchy in man, arising from the want of a force exercising the functions of an arbitrator between the mind and the heart, and inclining the latter to shape its decisions on the motives of the former. The truths, which he is frequently able to discover, satisfy his intellect without affecting his will, minister food to the mind, but operate not on the heart; in short, they establish a theory, but command not practice. Hence it often happens that man sees right, approves it, and yet adheres to wrong. Even after having gathered an abundant harvest from long studies and profound meditations, he still feels the need of a guide to direct his steps--of a means, available at all times, and competent to enable him to subordinate the appetitive to the intellectual faculties, and to cause the will to follow the judgments of the mind rather than those of the heart. XXVIII. The inadequacy of natural religion alone becomes still more manifest, when we consider the weakness and limited extent of the human understanding. To meditate assiduously on an abstract object, which does not fall under the perception of the senses, is given only to a few individuals endowed with uncommon penetration. But by far the greater part of men, disinclined to submit to long and arduous researches, concerning what they ought or ought not to believe and to do, prefer living thoughtlessly; and when they even try to enter upon spiritual meditations, they soon feel discouraged, and, often distrusting their own powers, throw up the difficult task half way, to resume the course of a reckless mode of life. XXIX. But even the few privileged beings, who believe themselves equal to the task, and plunge earnestly into spiritual researches, must confess to the insufficiency of the intellectual powers, and admit, that beside some few principles which they have succeeded in establishing, many doubts remain to be cleared, many questions to be solved, many objections to be overcome; and they must ultimately conclude, that reason by itself is unable to answer on all that interests man to admit or to deny, to seek or to avoid, to believe and to do, to hope and to fear. There is not, in this wide range of spiritual subjects, a proposition held by one as true, which has not been discarded by another as an error; and there is not a paradox or an absurdity that has not found some supporters, who maintained it as a truth. Doubt and error, in abstract and metaphysical questions, are natural and inherent in mankind, so long as reason is their only luminary in the research. XXX. The experience of all ages teaches us that the obstacles above stated have always exercised their influence upon the development of the moral sense among men, by retarding, and sometimes even rendering impossible to them, a clear and sound conception of their destination, and a firm resolve to conform to it.