• Man was destined for society. His morality therefore was to be formed to this object. He was endowed with a sense of right and wrong merely relative to this. This sense is as much a part of his nature as the sense of hearing, seeing, feeling; it is the true foundation of morality... The moral sense, or conscience, is as much a part of man as his leg or arm. It is given to all human beings in a stronger or weaker degree, as force of members is given them in a greater or less degree. It may be strengthened by exercise, as may any particular limb of the body.

    Thomas Jefferson: Man was destined for society. His morality therefore was to be formed to this object. He was endowed with a sense of right and wrong merely relative to this. This sense is as much a part of his nature as the sense of hearing, seeing, feeling; it is the true foundation of morality... The moral sense, or conscience, is as much a part of man as his leg or arm. It is given to all human beings in a stronger or weaker degree, as force of members is given them in a greater or less degree. It may be strengthened by exercise, as may any particular limb of the body.
    Thomas Jefferson's letter to Peter Carr, founders.archives.gov. August 10, 1787.