Scientists must use the simplest means of arriving at their results and exclude everything not perceived by the senses.
Ernst MachThe mathematician who pursues his studies without clear views of this matter, must often have the uncomfortable feeling that his paper and pencil surpass him in intelligence.
Ernst MachSimilarly, many a young man, hearing for the first time of the refraction of stellar light, has thought that doubt was cast on the whole of astronomy, whereas nothing is required but an easily effected and unimportant correction to put everything right again.
Ernst Mach