CAN THERE BE A SUM OF PLEASURES? 373 The question raised by this assertion is to my mind much more difficult and debatable than any that we have so far discussed, and the assertion that pleasures do admit of arithmetical measurement is in no way necessary to justify us in talking about a sum of pleasure or a hedonistic calculus. I hasten to add that as a general rule our judgments about pleasure are expressed in the form of " more " or " less," not of so many times more or less. It is only in the simplest cases that we can attempt to compare pleasures with so much nicety ; and, as such judgments are of no practical use, we do not commonly make them. Still, I am prepared to maintain that the judgment " this pleasure is twice as great as that " is not absolutely without meaning. In the first place, it appears to me self-evident that the value of a pleasure is dependent upon its duration, and that two minutes of a given pleasure may be fairly said to be twice as pleasant as one minute of it if it is really the same pleasure and is not diminished by satiety. Further, believing that we are in the habit of equating the intensity of pleasure with a certain duration of it, I hold that it is possible to indicate our sense of the comparative intensity of two pleasures by expressing them (so to speak) in terms of duration. If it is a matter of indifference to me whether I enjoy one minute of one pleasure or two minutes of another, I may reasonably be said to regard the one pleasure as twice as pleasant as the other. Even in far more complicated cases even in estimating the extent to which various elements contribute to a total state of continuous pleasure it does not seem to be meaningless to express one's sense of the comparative value of the different elements by assigning to them numerical values. In comparing one friend's dinners with another's there would be nothing unmeaning though for many practical reasons we rather avoid such exact mensura- tion of pleasures in assigning so many marks to the dinner, so many to the wine, so many to the conversation with (if you like) a few plus or minus marks for the arrangement of the table, the post-prandial music and so on. We might express our sense of the comparative enjoyment afforded by the two entertainments and the extent to which each element contributes to the total, by assigning marks to each such element and then adding them together. I admit that such numerical expressions would in general be wholly useless, but it would correctly express the sort of way in which we do make up our minds between alternative courses by a mental or ideal summation of the pleasure which we expect to derive from them. When we have
