Yet all these philosophers, as has been said, differ from one another more or less, both as to what they mean by Hedonism, and as to the reasons for which it is to be accepted as a true doctrine. The matter is therefore obviously not quite so simple as it might at first appear. My own object will be to shew quite clearly what the theory must imply, if it is made precise, if all confusions and inconsistencies are removed from the conception of it; and, when this is done, I think it will appear that all the various reasons given for holding it to be true, are really quite inadequate; that they are not reasons for holding Hedonism, but only for holding some other doctrine which is confused therewith. In order to attain this object I propose to take first Mill’s doctrine, as set forth in his book called _Utilitarianism_: we shall find in Mill a conception of Hedonism, and arguments in its favour, which fairly represent those of a large class of hedonistic writers. To these representative conceptions and arguments grave objections, objections which appear to me to be conclusive, have been urged by Professor Sidgwick. These I shall try to give in my own words; and shall then proceed to consider and refute Professor Sidgwick’s own much more precise conceptions and arguments. With this, I think, we shall have traversed the whole field of Hedonistic doctrine. It will appear, from the discussion, that the task of deciding what is or is not good in itself is by no means an easy one; and in this way the discussion will afford a good example of the method which it is necessary to pursue in attempting to arrive at the truth with regard to this primary class of ethical principles. In particular it will appear that two principles of method must be constantly kept in mind: (1) that the naturalistic fallacy must not be committed; (2) that the distinction between means and ends must be observed.