The South African philosopher Petrus Dreyer has pointed out that for Plato the Forms are the only real being outside the domains of time and space. And since the Forms represent the limited (peras), they are the opposite of the unlimited (apeiron), which is represented by the non-being of empty space (to kenon). It could also be said that as the negation of being, empty space exists only as a possibility. Dreyer adds that in Plato’s cosmology the world of phenomena is interposed between the extremes of that which is (to on) and that which is not (to mē on)—in other words, between true being and non-being. As Plato states in the dialogue Politeia, the sensible realm participates in both being and non-being (478d-e). The physical world is thus conceived as simultaneously real, through participating in the Forms, and unreal, through existing in non-being.64 In this way Plato establishes an ontological hierarchy of first the intelligible world (true being), then the sensible world (relative being, or becoming), and finally the abstract realm of non-being.
Ultimately, Philip Sherrard writes, Plato conceives of all things as partaking to some degree of the divine (since the Forms receive their reality from the Good, i.e., the One). It is precisely this phenomenon of participation which links the spiritual (or intelligible) world to the sensible world, including even the formless and the irrational. As Plato states in one of his late dialogues, the Timaeus (at 92c), the world (kosmos) is a sensible God made in the image of the Intelligible (eikon tou noētou theos aisthētos).65
As was done by his Platonic predecessors, so also Proclus explains the relation between the One and the many through the notion of participation. In his seminal work Elements of Theology, Proclus distinguishes between that which participates, that which is participated in, and that which is unparticipated (Propositions 23 and 24). This threefold scheme of participation has been illustrated by means of the following example: (i) a large thing, (ii) the largeness in the large thing, and (iii) the entity that possesses largeness paradigmatically (i.e., the Form of largeness).66
The Platonic concept of participation was employed by outstanding Christian thinkers such as Dionysius the Areopagite in the Greek tradition and John Scottus Eriugena in the Latin tradition. As Plato explains in the Phaedo, that which is determined (the effect) participates in its determination (the cause), through which the effect obtains the nature or attribute of the cause. Eric Perl comments that only by understanding Platonic participation can we understand the relation between cause and effect in Neoplatonism, and thus the sense in which, for Dionysius, God is the cause of all things.67 And Eriugena, within his profound synthesis of Greek and Latin Christian theology and Neoplatonic philosophy, presents participation as follows: the Creator (i.e., God as the beginning of all things) does not participate but is participated in; the primordial causes (i.e., the Forms, through which God creates the sensible world) participate in the Creator and is participated in; and the created effects participate in their primordial causes (Per III, 630). Only God as the end of all things neither participates nor is participated in.68
Continuing the Platonic and Patristic doctrine that the created world receives its being from God through participation, the Scholastic philosopher and theologian Thomas Aquinas opens his Treatise on Creation as follows: “All beings apart from God are not their own being, but are beings by participation.” Commenting on this quote, Wolfgang Smith suggests both an exoteric and an esoteric interpretation. From an exoteric viewpoint, it means that all things in the created order derive their being from God. This ontological dependence is illustrated by the example of red-hot iron, which receives its heat from fire, to which heat belongs essentially. However, from an esoteric viewpoint the above statement means that creatures possess a mere semblance of being, which actually belongs to none but God. In reality, the cosmos is a self-manifestation of God, which implies that in its theological conception as an ‘other than God’ the cosmos is really a pure nothing (Latin, purus nihil), as Meister Eckhart held. In the light of this reasoning, Smith concludes that the dichotomy of ‘Uncreated versus created,’ which is fundamental in Christian theology, may exist from the human point of view, but not in the sense of absolute truth.69
However, due to the lower receiving its being from the higher, the sensible world displays at least a measure of intelligibility.70 The Orthodox philosopher Philip Sherrard has remarked that the multiple Forms (or Ideas) are both transcendent in relation to the sensible objects determined by them, and immanent in these objects. As a result, he writes, “the creature possesses its own intelligible nature through actual participation in the creative cause which brought it into being.”71 We are able to discern harmony, proportion, and regularity in, for example: (a) the movements of the Sun, the Moon, and the planets, and therefore in the rhythms of day and night and of the seasons; (b) the life-cycles of organisms, from microbes through plants and animals to humans; and (c) the movements of sub-atomic particles as they interact to constitute material reality. Evidently, the physical world is not devoid of intelligibility, for example as order and harmony, even though it represents a lower reality than the metaphysical world.
By combining the concepts of being and non-being, as well the metaphysical and the physical, we arrive at the following hierarchy (arranged from most real to least real), which encompasses the totality of ‘something and nothing’:
i. Beyond-being (or God), which precedes the distinction between being and non-being;
ii. True being, which comprises the intelligible realm of unchanging Forms, at the apex of which is the universal Mind, or Intellect;
iii. Relative being (or becoming), which is the sensible world of ever-changing phenomena;
iv. Relative non-being, which is unformed matter;
v. Absolute non-being (or nothingness), which exists as an abstraction in human thought.
Relevance
Does this traditional ontology and metaphysics we have been discussing so far have any relevance to the physical world, including its sciences? The answer is a resounding ‘Yes.’ It has been argued, for example, that the standard model of quantum physics allows for the return of metaphysics in the sense in which Aristotle conceived it, after its expulsion from philosophy by Immanuel Kant and from science by nineteenth century materialism. Not only did it bring Being back into the picture of theoretical physics, but also Mind, as experimentation followed theorizing.72 Here are some quotes from eminent scientists: