I’ve recently been enjoying lectures posted by Ronald Nash (BiblicalTraining.org) on philosophical theology, which has stimulated thoughts about what he calls the rationalism of Plato versus the empiricism of Aristotle. I have generally held to a kind of scientific realism, as per Einstein’s philosophy of science, and T. F. Torrance’s applications to theology (“Transformation and Convergence in the Frame of Knowledge”); but I’m a nominalist when it comes to Plato’s forms. Conceptual categories (forms) of “things” are surely constructs. But there must be laws of nature that are timeless, universal and real – and these are laws that we “discover”, rather than construct. These laws define relationships: 1) causal relationships in science, pertaining to the dynamic reality of becoming (rather than being), in the tradition of Heraclitus; and 2) the logical relationships of mathematics. They are not universal forms that are imitated by particular things; they are rather universal rules that govern particular relationships. We infer this unseen reality from sensible phenomena, i.e. empirically, and construct models that correspond to it adequately for practical purposes. By God’s grace, the world is intelligible.
By analogy, I think it proper to say that moral imperatives are real, in that they are also “rules of the game” that specify ultimate consequences of behaviors (as taught in Proverbs), albeit in a rather nuanced way that transcends understanding (as per Job and Ecclesiastes). Virtues, on the other hand, are constructed conceptual categories.
Extrapolating to the ultimate reality, God is observable and known only in His activity (i.e. empirically), in creation and in history (e.g. Exodus 33:18-23). Consider also Hebrews 11:3, that the unseen cause of all that is seen is His word. This word, either as the Hebrew Torah or as the Greek Logos, is the organizing principle, the power, the Wisdom of God, which overcomes the chaos. Events in this space-time world – events of creation, providence, incarnation – reveal the timeless reality of the will (i.e. love) of God. And so His will and His Word are the final realities, and they can be known. At the level of the physical creation, the phenomena of supposed substance are ephemeral constructs, but the laws governing their dynamics are real. At the highest level of the “unseen”, the concept of “the Good” is a human construct, but the true reality is the One who is named: “I will be what I will be”.