Virtue is a habit of the mind, consistent with nature and moderation and reason.

The searching-out and thorough investigation of truth ought to be the primary study of man.

Friends are proved by adversity.

Superstition is an unreasoning fear of God.

There is in fact a true law namely right reason, which is in accordance with nature, applies to all men and is unchangeable and eternal. ... It will not lay down one rule at Rome and another at Athens, nor will it be one rule today and another tomorrow. But there will be one law eternal and unchangeable binding all times and upon all peoples.

Leisure consists in all those virtuous activities by which a man grows morally, intellectually, and spiritually. It is that which makes a life worth living.

Nature has circumscribed the field of life within small dimensions, but has left the field of glory unmeasured.