It is the mark of an educated mind to rest satisfied with the degree of precision which the nature of the subject admits and not to seek exactness where only an approximation is possible.
AristotleNeither old people nor sour people seem to make friends easily; for there is little that is pleasant in them.
AristotleA thing chosen always as an end and never as a means we call absolutely final. Now happiness above all else appears to be absolutely final in this sense, since we always choose it for its own sake and never as a means to something else.
Aristotle