Those whose days are consumed in the low pursuits of avarice, or the gaudy frivolties of fashion, unobservant of nature's lovelinessof demarcation, nor on which side thereof an intermediate form should lie.

Salt water when it turns into vapour becomes sweet, and the vapour does not form salt water when it condenses again. This I know by experiment. The same thing is true in every case of the kind: wine and all fluids that evaporate and condense back into a liquid state become water. They all are water modified by a certain admixture, the nature of which determines their flavour.

Knowledge of the fact differs from knowledge of the reason for the fact.

The whole is more than the sum of its parts.

Man is by nature a social animal; an individual who is unsocial naturally and not accidentally is either beneath our notice or more than human. Society is something that precedes the individual. Anyone who either cannot lead the common life or is so self-sufficient as not to need to, and therefore does not partake of society, is either a beast or a god.

Every virtue is a mean between two extremes, each of which is a vice.

Metaphysics involves intuitive knowledge of unprovable starting-points concepts and truth and demonstrative knowledge of what follows from them.