The method, then, which Von Hartmann recommends, viz., rational criticism of the quantities of pleasure and pain produced by life, has taught us so far how we are to get the data for our calculation, i.e., what we are to put down on the one side of our account and what on the other. But how are we to make the actual calculation? Is reason able also to strike the balance? A merchant makes a miscalculation when the gain calculated by him does not balance with the profits which he has demonstrably enjoyed from his business or is still expecting to enjoy. Similarly, the philosopher will undoubtedly have made a mistake in his estimate, if he cannot demonstrate in actual feeling the surplus of pleasure or, as the case may be, of pain which his manipulation of the account may have yielded. For the present I shall not criticise the calculations of those Pessimists who support their estimate of the value of the world by an appeal to reason. But if we are to decide whether to carry on the business of life or not, we shall demand first to be shown where the alleged balance of pain is to be found. Here we touch the point where reason is not in a position by itself to determine the surplus of pleasure or of pain, but where it must exhibit this surplus in life as something actually felt. For man reaches reality not through concepts by themselves, but through the interpenetration of concepts and percepts (and feelings are percepts) which thinking brings about (cp. pp. 82 ff.). A merchant will give up his business only when the loss of goods, as calculated by his accountant, is actually confirmed by the facts. If the facts do not bear out the calculation, he asks his accountant to check the account once more. That is exactly what a man will do in the business of life. If a philosopher wants to prove to him that the pain is far greater than the pleasure, but that he does not feel it so, then he will reply: "You have made a mistake in your theorisings; repeat your analysis once more." But if there comes a time in a business when the losses are really so great that the firm's credit no longer suffices to satisfy the creditors, bankruptcy results, even though the merchant may avoid keeping himself informed by careful accounts about the state of his affairs. Similarly, supposing the quantity of pain in a man's life became at any time so great that no hope (credit) of future pleasure could help him to get over the pain, the bankruptcy of life's business would inevitably follow. Now the number of those who commit suicide is relatively small compared with the number of those who live bravely on. Only very few men give up the business of life because of the pain involved. What follows? Either that it is untrue to say that the quantity of pain is greater than the quantity of pleasure, or that we do not make the continuation of life dependent on the quantity of felt pleasure or pain.