“That whose existence is necessary must necessarily be one essence.”

The more brilliant the lightning, the quicker it disappears.

Leeches should be kept a day before applying them. They should be squeezed to make them eject the contents of their stomachs.

There are no incurable diseases – only the lack of will. There are no worthless herbs – only the lack of knowledge.

I [prefer] a short life with width to a narrow one with length.

In God alone, essence (what He is) and existence (that he is) coincide.

An ignorant doctor is the aide-de-camp of death.

Now it is established in the sciences that no knowledge is acquired save through the study of its causes and beginnings, if it has had causes and beginnings; nor completed except by knowledge of its accidents and accompanying essentials.

It is in the nature of water … to become transformed into earth through a predominating earthy virtue; … it is in the nature of earth to become transformed into water through a predominating aqueous virtue.

Is it the fault of wine if a fool drinks it and goes stumbling into darkness?

As to the mental essence, we find it in infants devoid of every mental form.

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

When you do not know the nature of the malady, leave it to nature; do not strive to hasten matters. For either nature will bring about the cure or it will itself reveal clearly what the malady really is.

The different sorts of madness are innumerable.

Those who deny the first principle should be flogged or burned until they admit that it is not the same thing to be burned and not burned, or whipped and not whipped.

A horse is simply a horse.

Medicine considers the human body as to the means by which it is cured and by which it is driven away from health.

The very essence of instinct is that it’s followed independently of reason.

The essence of life is statistical improbability on a colossal scale.

Money is the alienated essence of man’s labor and life; and this alien essence dominates him as he worships it.

The Essence of Knowledge is, having it, to use it.

I think that in the essence of human civilization, we have the desire to become rich without limit, by taking the lives of other creatures.

I think that in the essence of human civilization, we have the desire to become rich without limit, by taking the lives of other creatures.

All science would be superfluous if the outward appearance and the essence of things directly coincided.

Love is something eternal; the aspect may change, but not the essence.