If however an objective estimate is attempted, thought gets speedily lost in a task impossible of achievement. Future pleasures and pains are influenced by two factors which are independent of present choice and effort. They depend upon our own state at some future moment and upon the surrounding circumstances of that moment. Both of these are variables which change independently of present resolve and action. They are much more important determinants of future sensations than is anything which can now be calculated. Things sweet in anticipation are bitter in actual taste, things we now turn from in aversion are welcome at another moment in our career. Independently of deep changes in character, such as from mercifulness to callousness, from fretfulness to cheerfulness, there are unavoidable changes in the waxing and waning of activity. A child pictures a future of unlimited toys and unrestricted sweetmeats. An adult pictures an object as giving pleasure while he is empty while the thing arrives in a moment of repletion. A sympathetic person reckons upon the utilitarian basis the pains of others as a debit item in his calculations. But why not harden himself so that others' sufferings won't count? Why not foster an arrogant cruelty so that the suffering of others which will follow from one's own action will fall on the credit side of the reckoning, be pleasurable, all to the good? Future pleasures and pains, even of one's own, are among the things most elusive of calculation. Of all things they lend themselves least readily to anything approaching a mathematical calculus. And the further into the future we extend our view, and the more the pleasures of others enter into the account, the more hopeless does the problem of estimating future consequences become. All of the elements become more and more indeterminate. Even if one could form a fairly accurate picture of the things that give pleasure to most people at the present moment--an exceedingly difficult task--he cannot foresee the detailed circumstances which will give a decisive turn to enjoyment at future times and remote places. Do pleasures due to defective education or unrefined disposition, to say nothing of the pleasures of sensuality and brutality, rank the same as those of cultivated persons having acute social sensitiveness? The only reason the impossibility of the hedonistic calculus is not self-evident is that theorists in considering it unconsciously substitute for calculation of future pleasures an appreciation of present ones, a present realization in imagination of future objective situations.