Whenever a doctor cannot do good, he must be kept from doing harm.

The dignity of a physician requires that he should look healthy, and as plump as nature intended him to be; for the common crowd consider those who are not of this excellent bodily condition to be unable to take care of themselves.

I have clearly recorded this: for one can learn good lessons also from what has been tried but clearly has not succeeded, when it is clear why it has not succeeded.

We must turn to nature itself, to the observations of the body in health and in disease to learn the truth.

The forms of diseases are many and the healing of them is manifold.

Men ought to know that from the brain and from the brain only arise our pleasures, joys, laughter, and jests as well as our sorrows, pains, griefs and tears. ... It is the same thing which makes us mad or delirious, inspires us with dread and fear, whether by night or by day, brings us sleeplessness, inopportune mistakes, aimless anxieties, absent-mindedness and acts that are contrary to habit.

Life is short, art long, opportunity fleeting, experiment uncertain, and judgment difficult.