There we have Prof. Sidgwick’s argument completed. We ought not, he thinks, to aim at knowing the Truth, or at contemplating Beauty, except in so far as such knowledge or such contemplation contributes to increase the pleasure or to diminish the pain of sentient beings. Pleasure alone is good for its own sake: knowledge of the Truth is good only as a means to pleasure. =52.= Let us consider what this means. What is pleasure? It is certainly something of which we may be conscious, and which, therefore, may be distinguished from our consciousness of it. What I wish first to ask is this: Can it really be said that we value pleasure, except in so far as we are conscious of it? Should we think that the attainment of pleasure, of which we never were and never could be conscious, was something to be aimed at for its own sake? It may be impossible that such pleasure should ever exist, that it should ever be thus divorced from consciousness; although there is certainly much reason to believe that it is not only possible but very common. But, even supposing that it were impossible, that is quite irrelevant. Our question is: Is it the pleasure, as distinct from the consciousness of it, that we set value on? Do we think the pleasure valuable in itself, or must we insist that, if we are to think the pleasure good, we must have consciousness of it too? This consideration is very well put by Socrates in Plato’s dialogue _Philebus_ (21 A). ‘Would _you_ accept, Protarchus,’ says Socrates, ‘to live your whole life in the enjoyment of the greatest pleasures?’ ‘Of course I would,’ says Protarchus. _Socrates._ Then would you think you needed anything else besides, if you possessed this one blessing in completeness? _Protarchus._ Certainly not. _Socrates._ Consider what you are saying. You would not need to be wise and intelligent and reasonable, nor anything like this? Would you not even care to keep your sight? _Protarchus._ Why should I? I suppose I should have all I want, if I was pleased. _Socrates._ Well, then, supposing you lived so, you would enjoy always throughout your life the greatest pleasure? _Protarchus._ Of course. _Socrates._ But, on the other hand, inasmuch as you would _not_ possess intelligence and memory and knowledge and true opinion, you would, in the first place, necessarily be without the knowledge whether you were pleased or not. For you would be devoid of any kind of wisdom. You admit this? _Protarchus._ I do. The consequence is absolutely necessary.