A careful physician . . . before he attempts to administer a remedy to his patient, must investigate not only the malady of the man he wishes to cure, but also his habits when in health, and his physical constitution.

Diseases of the soul are more dangerous and more numerous than those of the body.

Everyone has his besetting sin.

What is morally wrong can never be advantageous, even when it enables you to make some gain that you believe to be to your advantage. The mere act of believing that some wrongful course of action constitutes an advantage is pernicious.

Anyone may fairly seek his own advantage, but no one has a right to do so at another's expense.

They who say that we should love our fellow-citizens but not foreigners, destroy the universal brotherhood of mankind, with which benevolence and justice would perish forever.

All the arts, which have a tendency to raise man in the scale of being, have a certain common band of union, and are connected, if I may be allowed to say so, by blood-relationship with one another.