True friends visit us in prosperity only when invited, but in adversity they come without invitation.

Slovenliness is a lazy and beastly negligence of a man's own person, whereby he becomes so sordid as to be offensive to those about him.

Alcmaeon was the first to define the difference between man and animals, saying that man differs from the latter in the fact that he alone has the power of understanding.

Time is the most valuable thing a man can spend.

We must consider the distinctive characters and the general nature of plants from the point of view of their morphology , their behavior under external conditions, their mode of generation, and the whole course of their life.

I would define boastfulness to be the pretension to good which the boaster does not possess.

Waste of time is the most extravagant and costly of all expenses.