In a number of Plato’s works we find Socrates referring to instantiated properties as “partaking of” or “participating in” some universal property. A just act partakes of Justice, a beautiful horse participates in Beauty and so on. This kind of language is indicative of a metaphysical doctrine commonly referred to as Plato’s theory of Forms; a theory which Plato never explicitly expounds on and that is, according to my reading, rather inconsistent across certain dialogues. As is pointed out in this Stanford Encyclopedia of Philosophy entry:
What is referred to as Plato’s theory of Forms is thus a rational reconstruction of Plato’s doctrine. In such a reconstruction scholars try to determine a set of principles or theses which, taken together, allow us to show why Plato says what he does about Forms, souls, and other metaphysical items. In the attempt to make more precise what Plato is after, one risks attributing to Plato notions that are either not his or not as well developed in Plato as scholars would hope.
To summarise what that article examines at length with respect to the Forms, the contention is whether Forms have a separate, purely intelligible presence/existence or are always found — are immanent — in perceptible objects. As I have noted before (see all realisability posts), the immanence approach seems more plausible. The implication is that Forms are intelligible reformulations of perceptible properties; objects of thought that can remain constant in spite of [the potentiality of] change in the perceptible object(s) they are identified in.
Dog is inferred from
Labrador Retriever etc. as that set of qualities common among the multitude of instances.
Dog as such is never susceptible to the faculties of perception. That this dog is different from the neighbour’s dog which barks at night is irrelevant to the constancy of the intelligible object
Dog, because the latter only encapsulates the commonalities, not the factors of discernment. Similarly, that one cannot step into the same river twice because new waters always flow in (an argument for Universal flux by Heraclitus), is of no relevance whatsoever to the unchangeable quality of the notion of river — or of the very ideas of change and flux for that matter.
With regard to the language used, we may continue to employ terms that signify participation, with the understanding that we refer to the logical hierarchy which can be traced in the relationship between abstractions and their instantiations. As explained in my last post about classes, instances, differentiation the properties of the abstraction are all shared by its instances, while the properties germane to each instance, those that render them differentiable among the multitude of instances, are not found in the abstraction (all instances of
dog are extensions of
animal, not all instances of
animal are extensions of
By adopting this view we hope to avoid a whole range of dubious assertions Plato makes concerning recollection, the nature of the human soul and the like. However what we are certainly not pretending to do, is divorce logic and epistemology from their [sometimes tacitly assumed] metaphysical underpinnings. That some things have an abstract structure or can be known, if at all, presupposes an account of “some things”.
Thank you for reading!