§ 4. More serious, in my opinion, are the objections urged against the possibility of performing, with definite and trustworthy results, the comprehensive and methodical comparison of pleasures and pains which the adoption of the Hedonistic standard involves. I cannot indeed doubt that men habitually compare pleasures and pains in respect of their intensity: that (_e.g._) when we pass from one state of consciousness to another, or when in any way we are led to recall a state long past, we often unhesitatingly declare the present state to be more or less pleasant than the past: or that we declare some pleasant experiences to have been ‘worth,’ and others ‘not worth,’ the trouble it took to obtain them, or the pain that followed them. But, granting this, it may still be maintained (1) that this comparison as ordinarily made is both occasional and very rough, and that it can never be extended as systematic Hedonism requires, nor applied, with any accuracy, to all possible states however differing in quality; and (2) that as commonly practised it is liable to illusion, of which we can never measure the precise amount, while we are continually forced to recognise its existence. This illusion was even urged by Plato as a ground for distrusting the apparent affirmation of consciousness in respect of _present_ pleasure. Plato thought that the apparent intensity of the coarser bodily pleasures was illusory; because these states of consciousness, being preceded by pain, were really only states of relief from pain, and so properly neutral, neither pleasant nor painful--examples of what I have called the hedonistic zero--only appearing pleasant from contrast with the preceding pain.