Thus it forms no part of the present inquiry to follow out the application to conduct of different ethical ends, or to exhibit the different practical systems to which different ends naturally lead. It might seem indeed, at first sight, as if the development of their practical consequences might solve the question as to the nature of the ends themselves. If we assume certain possible and _primâ facie_ reasonable ethical ends, and then see what codes of morality they will yield, surely (it may be thought) that one which affords the most consistent and harmonious code for the guidance of life will be the end to be sought in preference to all others. But in order that the criticism of what Professor Sidgwick has called the methods of ethics may be able to answer the question as to the end or principle of ethics, certain conditions must first be complied with. In the first place, it is necessary that the ends or principles whose applications to conduct are to be examined must not be uncritically accepted from the fluctuating morality of common-sense nor from the commonplaces of the schools, but must be shown to be "alternatives between which the human mind" is "necessarily forced to choose when it attempts to frame a complete synthesis of practical maxims, and to act in a perfectly rational manner."[8] [Sidenote: (_bb_) from more than one self-consistent code being possible,] But although this requisite is complied with, it will still remain possible, in the second place, that two or more of the assumed principles may yield systems of practical rules perfectly self-consistent, and yet inconsistent with one another.[9] It would be very hard indeed to show that both the theory of Egoistic Hedonism, and what is generally called Utilitarianism, do not succeed in doing so: and thus the examination of methods is not of itself sufficient to settle the question of the end of conduct. And since--to quote Mr Sidgwick[10]--it is "a fundamental postulate of ethics that either these methods must be reconciled and harmonised, or all but one of them rejected," it follows that the criticism of methods leads naturally up to an independent criticism of principles, unless indeed it can be shown that one method only yields a consistent code of practical rules. [Sidenote: (_cc_) from its assumption that the true end must give perfectly consistent rules.]