only take place in consequence of a sufficient motive. Like causality in general, it is a natural law. On the other hand, moral laws, apart from human institution, state ordinance, or religious doctrine, cannot rightly be assumed as existing without proof. Kant, therefore, by taking such laws for granted, is guilty of a _petitio principii_, which is all the bolder, in that he at once adds (page vi of the preface) that a moral law ought to imply "=absolute necessity=." But "absolute necessity" is everywhere characterised by an inevitable chain of consequence; how, then, can such a conception be attached to these alleged moral laws (as an instance of which he adduces "thou shalt not lie"[1])? Every one knows, and he himself admits, that no such consecution for the most part takes place; the reverse, indeed, is the rule. In scientific Ethics before we admit as controlling the will other laws besides that of motivation-laws which are original and independent of all human ordinance--we must first prove and deduce their existence; that is, provided in things ethical we are concerned not merely with recommending honesty, but with practising it. Until that proof be furnished, I shall recognise only one source to which is traceable the importation into Ethics of the conception =Law, Precept, Obligation=. It is one which is foreign to philosophy. I mean the Mosaic Decalogue. Indeed the spelling "=du sollt="[2] in the above instance of a moral law, the first put forward by Kant, naïvely betrays this origin. A conception, however, which can\ point to no other source than this, has no right, without undergoing further scrutiny, thus to force its way into philosophical Ethics. It will be rejected, until introduced by duly accredited proof. Thus on the threshold of the subject Kant makes his first _petitio principii_, and that no small one.