This view is suggested by Mr. Herbert Spencer's statement---in a letter to J. S. Mill, published in Mr. Bain's Mental and Moral Science; and partially reprinted in Mr. Spencer's Data of Ethics, chap. iv. §21---that ``it is the business of moral science to deduce, from the laws of life and the conditions of existence, what kinds of actions necessarily tend to produce happiness, and what kinds to produce unhappiness'', and that when it has done this, ``its deductions are to be recognised as laws of conduct; and are to be conformed to irrespective of a direct estimate of happiness or misery.'' I ought, however, to say that Mr. Spencer has made it clear in his latest treatise that the only cogent deductions of this kind which be conceives to be possible relate to the behaviour not of men here and now, but of ideal men living in an ideal society, and living under conditions so unlike those of actual humanity that all their actions produce ``pleasure unalloyed with pain anywhere'' (Data of Ethics, §101). The laws of conduct in this Utopia constitute, in Mr. Spencer's view, the subject-matter of ``Absolute Ethics''; which he distinguishes from the ``Relative Ethics'' that concerns itself with the conduct of the imperfect men who live under the present imperfect social conditions, and of which the method is, as he admits, to a great extent ``necessarily empirical'' (Data of Ethics, §108). How far such a system as Mr. Spencer calls Absolute Ethics can be rationally constructed, and how far its construction would be practically useful, I shall consider in a later part of this treatise (Book iv. chap. iv.), when I come to deal with the method of Universalistic Hedonism: at present 1 am only concerned with the question how far any deductive Ethics is capable of furnishing practical guidance to an individual seeking his own greatest happiness here and now.