It is well known to researchers of nature that one cannot perform even the slightest movement without motivation, meaning without somehow benefiting oneself. When, for example, one moves one's hand from the chair to the table it is because one thinks that by putting one's hand on the table one will thus receive greater pleasure. If one would not think so, one would leave one's hand on the chair for the rest of one's life without moving it an inch, all the more so concerning greater efforts.