Often one feels that it is unjust on the part of destiny to put one into conditions that seem very cruel, and one thinks that it would be kinder on the part of destiny to teach without troubling. But what, after all, is trouble? There are no such things as pleasure and pain; only the comparison between them makes them so. In other words, if there was no pain one would not be capable of enjoying pleasure, and if there was no pleasure one would not be capable of experiencing pain. If that is true, then to the degree to which one is capable to experience pain, to the same degree one is able to experience pleasure. The one who cannot experience pain cannot experience pleasure. The stone has nothing, it has neither pleasure nor pain. It is the relativity, it is the relation, the comparison between two experiences which makes them distinct, but the one cannot be distinct without the other. Therefore there is the necessity of both experiences.