the heavenly gods, while the remaining three classes of living beings were made by these gods. Plato’s delegation of the rest of the creative work to the celestial gods may reflect a notion that the heavenly bodies, especially the Sun, actively generates life on Earth.117 We also read in the Politeia that the Sun is the cause of coming to be, growth, and nourishment of things in the visible world, without itself coming to be (Book VI, 509b).
Aristotle likewise recognized the influence of the Sun in the generation of living beings, as we read in the Physics: “Man is begotten by man and by the sun as well” (II.194). He suggests elsewhere that the efficient cause of things coming to be and passing away is the movement of the Sun towards and away from the earth: “Thus we see that coming-to-be occurs as the sun approaches and decay as it retreats; and we see that the two processes occupy equal times” (De Gen et Corr, II.336b). In other words, for Aristotle the generation and destruction of substance is caused by the annual movement of the Sun in the ecliptic or zodiac cycle.118
Antithesis: The Role of Necessity
Unlike the Judaic and Christian doctrine on God as creator, the Platonic Intellect is not viewed as omnipotent (or all-powerful) in fashioning the physical world. The reason for this limitation is that Intellect is constrained by an opposing force, which is necessity (Greek, anangkē; also translated as force or restraint).119 This view was already stated in mythical language by Parmenides, writing that Necessity is a goddess who governs all things. This includes the celestial bodies, which are led and shackled by necessity.120 Plato describes the role of necessity in the establishment of the cosmos as follows: “For this ordered world was of mixed birth: it is the offspring of a union of necessity and Intellect. Intellect prevailed over necessity by persuading it to direct most of the things that come to be towards what is best, and the result of this subjugation of necessity to wise persuasion was the initial formation of the universe” (Tim, 48a).
In the Platonic understanding, necessity is associated with disorder and random chance. Necessity means the indeterminate, the inconstant, the anomalous; it is a force that is irregular and unintelligible. In his informative commentary on the Timaeus, Francis Cornford writes further that necessity resides in the properties of the elements. For example, fire has a characteristic power (Greek, dynamis) to produce burning heat. Since necessity is constrained by its own nature, Plato calls it a wandering cause; in other words, a cause without purpose.121
Plato therefore mentions two types of causes, “distinguishing those which possess understanding and thus fashion what is beautiful and good, from those which, when deserted by intelligence, produce only haphazard and disorderly effects every time” (Tim, 46e). Nonetheless, the Demiurge uses these lower, auxiliary causes (synaitia) to produce the best result possible (Tim, 46c). The properties of these contributing structures are unalterable by the Demiurge, which is the reason why persuasion by Intellect is required for creation to take place.122 Necessity is therefore a second principle (archē) in the origin of things (Tim, 48b), next to Intellect.
The phenomenon of necessity was naturally explored by such a keen observer of nature as Aristotle, who made a distinction between two kinds of necessity. On the one hand there is absolute necessity, which is manifested in eternal phenomena, and on the other hand there is hypothetical necessity, which is manifested in everything that is generated by nature and everything that is produced by art (PA I.639b). A conspicuous example of hypothetical necessity is animals requiring food to live (PA I.642a). An important instance of absolute necessity is circular motion, such as that of the sun which ensures the continuity of alternate generation and destruction (De Gen et Corr, II.338a). Many other natural phenomena are due to absolute necessity, flowing inevitably from the nature of the specific matter.123 The effects of gravity would be a notable example of absolute necessity. Whereas Aristotle thus views absolute necessity as unrelated to final causality (due to lacking purpose), the hypothetical necessity in nature provides the conditions for an explanation in terms of final causality.124
It was further reasoned by Aristotle that the formation of a person’s eye serves a certain purpose in accordance with the reason (logos) of the individual, while the color of the eye is incidental and must ‘of necessity’ (ex anangkēs) be ascribed to its matter and moving cause (GA, 778a–b). Sometimes necessity even opposes purpose, as in the case of monstrous births that are due to defective matter (GA, 767b).125 This reasoning implies that tragic conditions such as physical deformity and mental retardation are due to material imperfections that could not be overcome by the activity of Intellect.
Aristotle’s well-known insistence on final causality, or teleology, enables him to indemnify the Prime Mover (which is his conception of the divine Intellect) from the imperfections in nature. Thus, imperfections in the structure of animals are ascribed to defective material, not a defective maker. This phenomenon is due to the fact that matter is sometimes not suitable for the purpose in hand, Aristotle suggested. In their turn, imperfections in individual organisms are due to the inherent variability of matter, since the latter is formed of an endless variety of combinations of the four elements.126 Nevertheless, final causality cannot be ignored, he writes: “Both causes must be stated by the physicist, but especially the end; for that is the cause of the matter, not vice versa” (Phys II.200a). By recognising the role of both final causality and necessity in the physical world, Aristotle continues Plato’s notion that the cosmos is the product of the interaction between the divine Intellect and irrational Necessity.
The phenomenon of physical deformity has been explained by Thomas Aquinas in terms of Aristotelian causality: “For if the matter is not disposed to receive the agent’s imprint [i.e., the operation of the efficient cause] a defect will follow in the effect, as when monsters are born because of unprepared matter: the fact that it doesn’t transform and actualize the indisposed matter can’t be laid at the door of the agent, for agents have powers proportioned to their natures and their inability to go further can’t be called deficiency in power; we can say that only when its power falls short of the measure laid down by nature” (Summa contra Gentiles, 3.10).
Synthesis: The Combination of Intellect and Necessity
After describing the role of Necessity, Plato devotes the next part of the Timaeus to a discussion of the physical cosmos, which is presented as the offspring of the union of Intellect and Necessity. Stated the other way around, Intellect persuades Necessity to form the initial universe: “For the generation of this universe was a mixed result of the combination of Necessity and Intellect. Intellect overruled Necessity by persuading her to guide the greatest part of the things that become towards what is best; in that way and on that principle this universe was fashioned in the beginning by the victory of reasonable persuasion over Necessity” (Tim, 48a; Cornford’s translation). As Plato concludes, “That is why we must distinguish two forms of cause, the divine and the necessary” (Tim, 68e).
However, the result of the restriction of the activity of Intellect by irrational Necessity is that the physical world displays both design and accident, is both purposeful and contingent, and harbours both good and bad. This statement should not be confused with Gnostic dualism, according to which the world is inherently evil due to its creation by an inferior deity. In the traditional understanding, evil is not self-existing but follows from a privation of goodness, just as darkness is due to an absence of light.
Within this context of the interaction between Intellect and Necessity, Plato situates
