Fī mā baʿd al-ṭabīʿa

(lit.: On Metaphysics)

A short treatise that refuses to take nature on trust and puts hard questions to Aristotle and Galen.

Arabic, the original language

Original language: Arabic

Overview

Aristotle held, in the second book of his Physics, that the existence of nature needs no proof because everyone admits it, and his later readers added that nature shows itself in what it does: fire rises, earth falls, plants take food and grow. The short Arabic treatise Fī mā baʿd al-ṭabīʿa (On What Comes After Nature) opens by refusing both claims. Agreement does not make a thing true, its author answers, any more than disagreement makes it false, and some ancient philosophers denied that nature exists at all. What follows is not a commentary but an independent polemic against everyone who makes nature the source of motion. Galen, the Greek physician, is caught calling nature's shaping of the teeth and mouth deliberate, though elsewhere he gives deliberate action to the soul alone. Living creatures, the treatise adds, govern nature with diet and drugs, rather than nature governing them. It asks what gives form to an embryo or to an insect born in the earth. Aristotle held the world finite in extent but without a beginning in time; the treatise asks why, if every motion has another before it, he does not also say that every stretch of space has another beyond it. The text closes on the puzzle of a man at the world's edge stretching out his hand. Paul Kraus included it in his 1939 Cairo edition of al-Razi's philosophical writings, though some scholars have doubted that it is his.

Key concepts

What is the 'nature' that the treatise puts on trial?

Nature, ṭabīʿa, is the principle the philosophers said moves bodies and brings forth growth from within: what makes fire rise, earth fall and plants feed. The treatise notes that this nature is neither seen nor known by reason, and that its defenders give it the marks of a creator, wise governance and permanence, while denying it life, perception and will. That combination is the target of the whole book.

Why does acting for an end require a living agent?

To act for the sake of something, an agent must be alive, able and aware of the benefit it aims at. A carpenter builds for a purpose, the craft of carpentry does not build at all. So saying that lifeless nature acts without thought or will, yet not by chance and for an end, joins two claims that cannot both hold. Calling it 'natural' purpose only renames the problem.

Why is being present when something happens not the same as causing it?

Semen is present whenever an embryo forms, but it can also be present when no embryo forms, so its presence alone does not show that it shapes the embryo. The treatise uses the same test elsewhere: a fact observed in one place, or a constant companion of an event, is not yet its cause. A cause has to be demonstrated, not inferred from what happens to be there.

What is an actual infinite, and why does the treatise doubt one in the past?

An actual infinite is an endless quantity that exists all at once, as the whole past would if motion had no beginning. The treatise asks whether such a series can have a half, or grow by each new motion; if it can be added to, it has a limit on that side. The doubt is aimed at Aristotle's world, finite in space yet beginningless in time.

Themes of the book

What this book returns to, gathered into themes and ordered by how much of the text each one occupies.

Nature on Trial

Can something lifeless, without sight or knowledge, be the wise cause of an ordered world? The treatise demands proof where the philosophers took it for granted.

Aristotle's followers made nature the source of motion and growth: fire rises, plants feed, embryos take shape, and all of it for an end. The treatise answers that acting for an end needs a living agent who knows the benefit, as a carpenter does and the craft of carpentry does not. Galen is caught praising nature's wise shaping of the teeth while reserving deliberate action for the soul. Defects in animals and ruinous weather sit badly with a wise nature, and the living creature governs its body with diet and drugs.

nature
teleology
agency
causation
generation
biology
evidence
consensus
craft
defects
natural evil
divine action

Enter a dialogue

Did Motion Have a Beginning?

If every motion has another before it, why should every stretch of space not have another beyond it? The question turns Aristotle's eternal world against itself.

Aristotle kept the world finite in extent but gave its motion no beginning. The treatise presses the asymmetry from several sides. A series of past motions without end would have to have a half and keep growing, which an infinite cannot do. Treating the heavens' motion as one single movement makes the same motion both past and present. The villager who thinks the fields go on forever is a warning about inferring the infinite from the familiar, and the hand stretched out at the world's edge proves no void beyond it.

motion
infinity
time
eternity
cosmology
space
boundaries
multiple worlds
temporal identity
imagination
creation

Enter a dialogue

Within this work

passages held: 26
distinct concepts: 44
by passages held, corpus-wide: #752

What this book thinks together

The wheel takes this book’s leading concepts and shows how often they come up together. The wider the band between two, the more of its passages speak of both. Among them, most often together: “nature” and “teleology”.

Concept co-occurrence, strongest first 7 concepts, joined by 11 pairings. 24 pairings reach beyond these concepts and are not drawn.
Concept	Paired concept	Shared passages
nature	teleology	9
agency	nature	7
agency	teleology	6
causation	nature	5
infinity	motion	4
causation	teleology	3
induction	motion	2
motion	nature	2
agency	causation	1
causation	induction	1
causation	motion	1

Works held

The author's work in order, this book marked in place. Your-language title first, the original beneath it where the two differ; side chips show which full texts are held.

Fī mā baʿd al-ṭabīʿa you are here AR
The Book of the Philosophic Life (al-Sīra al-falsafiyya)
A short apologia in his own voice, which sends its reader to al-Ṭibb al-rūḥānī (Spiritual Medicine) for the detailed cure of each vice.
AR
The Spiritual Physick (al-Ṭibb al-rūḥānī)
The longer of al-Razi's two complete surviving works on ethics: twenty short chapters of advice, addressed to his patron, the governor of Rayy.
AR

— or open another of their works