If the soul served to connect the eternal realities with the fleeting appearances by which they were at once darkened, relieved, and shadowed forth, it was also a bond of union between the speculative and the practical philosophy of Plato; and in discussing his psychology we have already passed from the one to the other. The transition will become still easier if we remember that the question, ‘What is knowledge?’ was, according to our view, originally suggested by a theory reducing ethical science to a hedonistic calculus, and that along with it would arise another question, ‘What is pleasure?’ This latter enquiry, though incidentally touched on elsewhere, is not fully dealt with in any Dialogue except the _Philêbus_, which we agree with Prof. Jowett in referring to a very late period of Platonic authorship. But the line of argument which it pursues had probably been long familiar to our philosopher. At any rate, the _Phaedo_, the _Republic_, and perhaps the _Gorgias_, assume, as already proved, that pleasure is not the highest good. The question is one on which thinkers are still divided. It seems, indeed, to lie outside the range of reason, and the disputants are accordingly obliged to invoke the authority either of individual consciousness or of common consent on behalf of their respective opinions. We have, however, got so far beyond the ancients that the doctrine of egoistic hedonism has been abandoned by almost everybody. The substitution of another’s pleasure for our own as the object of pursuit was not a conception which presented itself to any Greek moralist, although the principle of self-sacrifice was maintained by some of them, and especially by Plato, to its fullest extent. Pleasure-seeking being inseparably associated with selfishness, the latter was best attacked through the former, and if Plato’s logic does not commend itself to our understanding, we must admit that it was employed in defence of a noble cause. The style of polemics adopted on this occasion, whatever else may be its value, will serve excellently to illustrate the general dialectic method of attack. When Plato particularly disliked a class of persons, or an institution, or an art, or a theory, or a state of consciousness, he tried to prove that it was confused, unstable, and self-contradictory; besides taking full advantage of any discredit popularly attached to it. All these objections are brought to bear with full force against pleasure. Some pleasures are delusive, since the reality of them falls far short of the anticipation; all pleasure is essentially transitory, a perpetual becoming, never a fixed state, and therefore not an end of action; pleasures which ensue on the satisfaction of desires are necessarily accompanied by pains and disappear simultaneously with them; the most intense, and for that reason the most typical, pleasures, are associated with feelings of shame, and their enjoyment is carefully hidden out of sight.