Ibn Sina (Avicenna)

The knowledge of anything, since all things have causes, is not acquired or complete unless it is known by its causes.

Imagination is the eye of the soul.

The more perfect a thing is, the more susceptible it is to corruption.

Medicine is a science from which one learns the states of the human body in health and disease, in order to preserve health when it exists and restore it when it has been lost.

The soul, by its very nature, is a simple substance, not composed of parts, and therefore cannot be dissolved into its parts.

Ignorance leads to fear, fear leads to hatred, and hatred leads to violence. This is the equation.

The world is divided into men who have brains and men who have not. The former are few, the latter are many.

The physician should have a good knowledge of the patient's constitution, temperament, and habits, as well as the nature of the disease.

The purpose of medicine is to prolong life, and to shorten the period of suffering.

The human body is a complex machine, and its parts are interconnected in a marvelous way.

The best way to preserve health is to live a temperate life, and to avoid excesses of all kinds.

The mind is the ruler of the body, and it has a great influence on its health and disease.

The physician must be a man of integrity, compassion, and wisdom.

The more you know, the more you realize you don't know.

The soul is not a body, nor is it in a body, but it is the form of the body.

The universe is a single, interconnected whole, and all its parts are in harmony with each other.

The greatest disease is to be without hope.

The physician should be a philosopher, for he who is not a philosopher is not a physician.

The human being is a microcosm, reflecting the macrocosm of the universe.

The purpose of life is to seek knowledge and to live in accordance with reason.