Paracelsus

All things are poison, and nothing is without poison; only the dose makes it so a thing is not a poison.

The dose makes the poison.

The art of medicine is to be learned from nature, not from books.

The physician must be a man of prayer, for he must pray for the sick.

The patient is the book, and the disease is the teacher.

Nature is the physician, and the physician is only nature's assistant.

The true physician is a man who knows how to heal, not a man who knows how to talk.

The physician must be a philosopher, an astronomer, an alchemist, and a theologian.

The physician must have a good heart, for he must love his patient.

The physician must be a man of courage, for he must face death.

The physician must be a man of faith, for he must believe in God.

The physician must be a man of hope, for he must hope for the best.

The physician must be a man of charity, for he must give to the poor.

The physician must be a man of humility, for he must know his limitations.

The physician must be a man of wisdom, for he must know the truth.

The physician must be a man of knowledge, for he must know the secrets of nature.

The physician must be a man of experience, for he must have seen many diseases.

The physician must be a man of observation, for he must see what others do not see.

The physician must be a man of judgment, for he must make the right decisions.

The physician must be a man of skill, for he must be able to perform operations.