Translated with introduction and notes by A.E. Taylor

Historical Value of Aristotle's Criticism← TOC→Chronological Table


Intellectual curiosity a fundamental natural instinct, as is shown by the fact that sense-perceptions are normally pleasant in themselves. The successive stages in the development of rational cognition: sensation, primary memory, experience, art or science [i. e., bodies of general truths which involve a theory as to the reason of facts and a systematic classification of them]. General theory, though often less serviceable for immediate practice than experience, holds a higher rank in the series of intellectual activities, because it involves insight into the cause or reason of facts; hence, we regard it as revealing a superior degree of Wisdom. Historically, human intelligence was first employed in providing for the necessities, and then for the comforts, of existence; science arose, in Egypt, from the existence of a priestly caste for whose necessities and comforts adequate provision had already been made, and who therefore were at leisure to employ their intellect upon speculative inquiry into the reasons and causes of things.


What is the general character of that highest form of intellectual activity which is traditionally known as "Wisdom?" By universal consent, Wisdom possesses the following characteristics: (1) universality of range (conversance with the universal presuppositions of all cognition); (2) profundity; (3) ultimate certainty and validity; (4) finality in its explanations; (5) scientific disinterestedness; (6) independence of immediate practical needs. All these characteristics will be found to belong in a superlative degree to the scientific investigation of the ultimate causes and principles of existence. The original incentive to such investigation is the sense of wonder and perplexity in the presence of facts which we are unable to explain. The science thus originated, because independent of all practical interests, is the only really liberal science. It also, more than any other form of knowledge, is "divine," for the double reason that it involves the contemplation of divine objects and that it is the only form of cognition worthy of divine intelligences.


Our object, then, is the analysis and classification of the different kinds of cause. In the Physics we have distinguished four senses of the term: (1) the formal, (2) the material, (3) the efficient, (4) the final cause. A review of the past history of philosophical thought will confirm our confidence in the exhaustiveness of this analysis if we find that every principle of explanation employed by previous thinkers can be classed under one or other of these four heads.

Now, the earliest philosophers asked only: What is the material cause of things--i. e., what is the primitive and indestructible body of which all sensible things are perishable transformations? Thales, whose reasons for his opinion can only be conjectured, said that it is water (a view which perhaps has some support in early poetical tradition); Anaximenes and Diogenes, that it is air; Heraclitus and Hippasus, that it is fire; while Empedocles assumes the existence of four such primitive forms of body; Anaxagoras, of an infinite number. This leads to a second problem. By what agency have the various transformations of the primary body or bodies been produced; what is the efficient cause of the physical world? The early Monists ignored this problem, with the exception of the Eleatic school, who met it by asserting that change itself is a mere illusion. Parmenides, however, and the later pluralistic Physicists (Empedocles, Anaxagoras) provide some material for its solution by assigning to some elements an active, to others a passive role in the formation of things.

A further question which obviously suggests itself is the problem: What is the explanation of the presence of Order, Beauty, Goodness, and their opposites in the universe--i. e., what is the final cause of existence? The first explicit recognition of such a final cause is contained in the declaration of Anaxagoras that Mind is the source of all cosmic order.


Still earlier implicit hints of a teleological explanation of things may be found in those writers who treat sexual Desire as a formative principle. (Hesiod, Parmenides.) Empedocles goes a step farther in recognizing Strife as well as Love as a native impulse in the universe, thus half-consciously introducing a double teleological principle, a cause of Good and a contrasted cause of Evil. But neither Anaxagoras nor Empedocles has a really consistent and well thought-out philosophy. Anaxagoras, in the actual working-out of his scheme, treats Mind as a mere mechanical agent, and only falls back upon it when he cannot find a specific physical mechanical cause of a given state of things. In Empedocles Strife is, in fact, just as much a cause of organic combinations as Love, and Love as much a source of dissolution as Strife, and though he professes to recognize four equally ultimate "elements," he really assigns a special active function to Fire and treats the other three, in contrast with Fire, as a single passive principle.

The Atomists, again, Leucippus and Democritus, consider only the problem of the material cause, which they solve by recognizing a pair of contrasted factors--Body, which consists of an infinity of solid atoms, and Void, or Empty Space, as the ingredients of which things are made.


Meanwhile, the Pythagorean mathematicians were led, by fanciful analogies between the properties of numbers and those of visible things, to the view that physical things are made of numbers and that the constituent elements of number (which are the Even and Odd, or Unlimited and Limit) are the ultimate elements of the universe. In order to carry out this correspondence between numbers and things, they allowed themselves a wide license in the invention of imaginary objects. Some of them, following hints unsystematically thrown out by Alcmaeon of Crotona, constructed a list of ten contrasted pairs of "opposite" principles. Their doctrine is obscure and confused, but it is clear that they meant to say that the elements of number are the material causes or constituent factors of things.

The Eleatics, who regarded the Universe as a simple Unity, were in consistency debarred from any inquiry into causation, since on their view all change and all processes of origination must be subjective illusions. Parmenides, however, affords some reconciliation of the Monistic doctrine with actual experience, since he seems to hold that though Being is one from the point of view of rational thought, it is many from that of sensation. Hence, in the cosmological part of his poem he treats not-Being as a causative principle opposed to and co-ordinate with Being, and thus reverts to a kind of Dualism. The cruder views of Melissus and Xenophanes call for no consideration.

Thus we see that all these philosophers recognize the existence of a material cause or causes, though they disagree about their number. They also recognize the existence of efficient causality, though some of them postulate a single initial motive impulse, others a pair of contrasted impulses. The Pythagoreans, also, adopted a dualist explanation of things, but they differed from other thinkers in holding that number and its elements are not predicates of some sensible reality, but the actual substance or stuff of which things are made. They further tentatively began to give definitions of some things and thus to recognize the principle of the formal cause, though in a crude and superficial way.


The system of Plato, though in general analogous to that of the Pythagoreans, has some special peculiarities. From early association with Cratylus, the Heraclitean, he derived a fixed conviction that sensible things, being essentially variable and mutable, cannot be defined. Hence, having been led by the example of Socrates to regard universal definition as the fundamental problem of science, he inferred that the objects of scientific cognition are a separate class of supra-sensible entities, which he called "Ideas," and that the corresponding classes of sensible things are connected with them by a peculiar relation which he called "participation," but the Pythagoreans "imitation." The nature of this relation was left unexplained. He further held that the objects of Mathematics form a third class of entities, intermediate between "Ideas" and sensible things. Like the "Ideas," they are immutable; like sensible things, there are many of each kind.

The "Ideas" being the causes of everything else, their constituent elements are ultimately the constituent elements of everything. These elements are two, a material principle, the "Great and Small," and a formal principle, the One. From the union of these two proceed the "Ideal Numbers." Thus he agreed with the Pythagoreans in holding (1) that numbers are the causes of all Being, and (2) that they are independent entities and not mere predicates of anything more ultimate. He differed from them in (1) taking as his material principle or Unlimited a duality of the "Great and Small" and (2) in regarding numbers as entities of a different kind both from sensible things and from mathematical objects.

Thus we see that this theory recognizes two forms of cause, the formal and the material. Incidentally, also, he follows the lead of Empedocles in regarding one of these factors, the One, as the cause of Good, the other as the cause of Evil.


We see, then, that every type of cause recognized in earlier philosophy is provided for in our fourfold classification. The material cause appears in one shape or another in the philosophies of Plato, the Pythagoreans, Empedocles, Anaxagoras, the Ionian Monists. The efficient cause has received recognition from Empedocles and Anaxagoras, not to mention the poets who have found a cosmic principle in sexual Desire. The nearest approximation to the conception of a formal cause or constitutive law is to be found in Platonism, according to which the Ideas constitute the what or essential nature of things, the One that of the Ideas. As for the final cause, it has in a way been recognized by Empedocles, Anaxagoras and Plato, but not in its true character. Thus our historical retrospect affords some presumption that our fourfold classification of causes is complete. It remains to point out the main defects of the various systems.


Monistic Materialism (the doctrine of the Milesians Heraclitus, etc.) is defective (1) because its explanations are only applicable to corporeal things, whereas there exist also things which are incorporeal; (2) because it renders the fact of phenomenal change inexplicable, from its inability to recognize efficient causality; (3) because it ignores inquiry into the formal causes or constitutive laws of things; (4) because the Monistic Materialists proceed on no intelligible principle in their selection of the primary body. We may suppose other bodies to be produced from this primary body either by a process of concretion or by one of disintegration; and again, we may hold that on either view, the temporal starting-point of the process is identical with its final result, or that it is opposite. Whichever of these alternatives be adopted, we can only reasonably regard either the densest form of matter (earth) or the least dense (fire) as the primary body. The early Monists overlooked this, and selected their primary body at haphazard. The pluralistic materialist, Empedocles, is exposed to some of the same difficulties, and there are also special objections to his doctrine. (1) He holds that the "simple bodies" are not reciprocally convertible into each other, whereas we see, in fact, that they do pass into one another. (2) His account of efficient causality is neither correct nor consistent with itself. (3) His general position involves denial of the reality of all qualitative change. As for Anaxagoras, his doctrine of the original intermixture of all things is open, as it stands, to the following objections: (1) If such a "mixture" ever existed, there must have been a previous period during which its ingredients existed unmixed; (2) it is not true in fact that everything will "mix" with everything else; (3) what is united by "mixture" is also separable; hence, if qualities belong to things by being "mixed" with them, it should be possible to separate the "mixture" and obtain pure qualities without any corresponding substances. Probably, then, his language about the "mixture" was merely an inadequate attempt to formulate the conception of a common material substrate in physical things devoid of all determinate sensible quality. If so, his doctrine amounts to a dualism of Mind and an indeterminate Matter which closely anticipates the Platonic dualism of the One and its Other, the "Great and Small."

The doctrine of the Pythagoreans, though apparently of a more abstract character, was also really intended as a cosmology. They too, like the early physicists just discussed, held that what is consists entirely of perceptible physical bodies, though their principles would really have been more in place in a system of abstract Mathematics than in Physics. They cannot possibly deduce real motion from their purely mathematical principles, nor can they give any account of the physical properties of body. The cosmical causality they ascribe to number is unintelligible if there is only one kind of numbers and these are identical with physical things.


To the Platonist doctrine of Ideas or "Ideal Numbers" we may object: (1) That it merely duplicates the unsolved problems of the sensible world by postulating a precisely similar "ideal" world as its counterpart. (2) The supposed proofs of the existence of Ideas are all fallacious. Some of them would require the existence of Ideas of artificial objects and of negatives, others that of Ideas of the perishable. The most exact of them lead either to the admission of Ideas of relatives or to the indefinite regress. (3) The arguments for the theory of Ideas involve assumptions inconsistent with the Platonic view of the One and the "Great and Small" as the primary elements of Being.

(4) Those arguments are also inconsistent with the theory of the "participation" of things in the Ideas. According to the former, there must be Ideas corresponding to every logical category of general names, whereas it is implied by the doctrine of participation" that there can only be Ideas of substances.

(5) The Ideas are useless as principles for the explanation of the sensible world. (1) They do not account for our knowledge of the things, since, by hypothesis, they are outside them, in a world of their own. (2) For the same reason, they do not account for the Being of other things. (3) Nor do they account for the production of other things. "Participation," "archetype," etc., are mere empty metaphors. For who is the artist who constructs things on the model of these archetypes? Further, it will follow that there can be several archetypes of the same thing, and also that some Ideas are archetypes of other Ideas.

The mere existence of a Platonic Idea is insufficient to cause the existence of a corresponding sensible thing; and, on the other side, some things come into being of which the Platonists do not recognize Ideas.

(6) Special difficulties arise from the view that the Ideas are a class of Numbers. (a) How on such a view are we to understand the assertion that they are causes of sensible things? (b) What relation among Ideas corresponds to the arithmetical relations between numbers which are combined by addition into a sum? (c) The theory requires us to construct a further class of numbers which are to be the objects of arithmetic. (d) It is difficult to reconcile the assertion that the Ideas are numbers with the other assertion that they are substances.

(7) It is quite impossible to bring the fundamental concepts of geometry into connection with the Platonic theory of the One and the "Great and Small" as the universal con­stituents of Being. Plato had seen the difficulty, so far as points are concerned, and had consequently refused to recog­nize their existence. But the same line of argument which establishes the existence of lines is equally valid for that of points.

(8) In short, the Ideal Theory is the substitution of mere Mathematics for Philosophy, and merely duplicates the problems of the sensible world. It throws light neither on efficient nor on final causation. Even the conception of matter in this philosophy is mathematical rather than physical, and, as to motion, its very existence is inconsistent with the principles of the theory. Not to mention the impossi­bility of finding any place whatever in the Platonic scheme for certain important geometrical entities.

(9) In general, we may say that Plato has fallen into the error of supposing that all objects of cognition are com­posed of the same universal elementary constituents, and that these are discoverable by analysis. But the truth is (a) that analysis into constituent elements is impossible except in the case of substances, and (b) all acquisition of knowledge presupposes previous knowledge as its basis. Hence, the Platonic conception of a single all-comprehensive science of Dialectic which analyses all objects into their elements is chimerical. Even if it were not, one could at least never be sure that the analysis had been carried to completion. Also the Platonic philosopher, who knows the elements of everything, ought to be able to know sense-qualities with­out needing to have experienced the corresponding sensa­tions.


Thus we see that all our four significations of the term "cause" have emerged in past speculation, and no others. But the real sense and import of the principles employed has been only confusedly and dimly perceived. Even Em­pedocles, e.g., had a dim glimpse into the significance of formal causes or constitutive laws, though he was unable to give distinct expression to his thought.

Created for Peithô's Web from Aristotle on his predecessors; being the first book of his Metaphysics; tr. from the text edition of W. Christ, with introd. and notes by A. E. Taylor. Chicago, Open Court, 1907.Taylor's footnotes have been converted to endnotes. Greek unicode text entered with Peithô's Younicoder.
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