The idea of disembodied spirits is wholly unsupported by evidence, and I cannot accept it.
Herbert SpencerIf a single cell, under appropriate conditions, becomes a man in the space of a few years, there can surely be no difficulty in understanding how, under appropriate conditions, a cell may, in the course of untold millions of years, give origin to the human race.
Herbert SpencerOrgans, faculties, powers, capacities, or whatever else we call them; grow by use and diminish from disuse, it is inferred that they will continue to do so. And if this inference is unquestionable, then is the one above deduced from it-that humanity must in the end become completely adapted to its conditions-unquestionable also. Progress, therefore, is not an accident, but a necessity.
Herbert Spencer