Aristotle

The greatest wealth is to live content with little.

Democracy is when the indigent, and not the men of property, are the rulers.

It is not enough to win a war; it is more important to organize the peace.

The true disciple is not he who has learned most, but he who has learned best.

The wise man does not expose himself needlessly to danger, since there are few things for which he cares sufficiently; but he is willing, in great crises, to give even his life — knowing that under certain conditions it is not worthwhile to live.

The end of labor is to gain leisure.

Piety requires us to honor truth above our friends.

The one exclusive sign of thorough knowledge is the power of teaching.

The animal is a living body endowed with sensation.

The species is a collection of individuals that are similar in form and function.

Every animal has a purpose, and its parts are adapted to that purpose.

The growth of an animal is a continuous process of change and development.

Observation is the foundation of all knowledge.

The natural world is full of wonders, and it is our duty to explore and understand them.

The difference between man and other animals is that man has reason.

The best life is one of contemplation and intellectual activity.

Character may almost be called the most effective means of persuasion.

He who has overcome his fears will truly be free.

It is well to be informed about the reasons for the faith in which you believe.

The true biologist is not repelled by the study of any kind of animal.