Reason is a necessary condition for conscience, but only because without the former a clear and connected recollection is impossible. From its very nature conscience does not speak till =after= the act; hence we talk of being arraigned before its =bar=. Strictly speaking, it is improper to say that conscience speaks =beforehand=; for it can only do so indirectly; that is, when the remembrance of particular cases in the past leads us, through reflection, to disapprove of some analogous course of action, while yet in embryo.
Such is the ethical fact as delivered by consciousness. It forms of itself a metaphysical problem, which does not directly belong to the present question, but which will be touched on in the last part.
Conscience, then, is nothing else than the acquaintance we make with our own changeless character through the instrumentality of our acts. A little consideration will show that this definition harmonises perfectly with, and hence receives additional confirmation from, what I have here specially emphasised: namely, the fact that =susceptibility= for the motives of Egoism, of Malice, and of Compassion, which is so widely dissimilar in different individuals, and on which the whole moral value of a man depends, cannot be interpreted by anything else, nor be gained, or removed, by instruction, as if it were something born in time, and therefore variable, and subject to chance. On the contrary, we have seen that it is innate and fixed, an ultimate datum, admitting of no further explanation. Thus an entire life, with the whole of its manifold activity, may be likened to a clock-dial, that marks every movement of the internal works, as they were made once for all; or it resembles a mirror, wherein alone, with the eye of his intellect, each person sees reflected the essential nature of his own Will, that is, the core of his being.
Whoever takes the trouble to thoroughly think out what has been put forward here, and in Part. II., Chapter VIII., will discover in the foundation given by me to Ethics a logical consecution, a rounded completeness, wanting to all other theories; to say nothing of the consonance of my view with the facts of experience,--a consonance which he will look for in vain elsewhere. For only the truth can uniformly and consistently agree with itself and with nature; while all false principles are internally at variance with themselves, and externally contradict the testimony of experience, which at every step records its silent protest.