Man’s essential characteristic is his rational faculty. Man’s mind is his
basic means of survival—his only means of gaining knowledge . . . .
In order to sustain its life, every living species has to follow a certain
course of action required by its nature. The action required to sustain human
life is primarily intellectual: everything man needs has to be discovered by
his mind and produced by his effort. Production is the application of reason
to the problem of survival.