I was sitting down looking at an orchard whilst pondering Ockham and Scotus.
Nominalism, Realism, the Particular, the Universal.
What is a tree? What is THIS tree? What is essence? What is the essence of essence?
It seems to me that there are no universal essences except those which occur within natural objects. And the measure of this reality is the fact of reproduction. In natural reproduction there is reproduced two things which are one, but formally distinct- the universal and the particular.
The oak tree gives birth to the oak tree, not the pine tree. Therefore, that immaterial constraint which acts upon matter giving it the form of an oak and nothing else is substantial form. It can partially be represented mathematically as the laws governing chemical reactions, but is fundamentally immaterial, but held within matter. The laws therefore governing the growth and reproduction of oak trees are at least in part, the substantial form of an oak, and the matter this form acts upon and within is what makes an oak tree.
However, because of the variety of matter, each element of which has its own form, and because of the imperfection and weakness of individual substances, not all oak trees are identical. One receives more or less sun, more or less water and more or less heat. Moreover, one receives more or less genetic material (which has its own form) and the chemical process in each may be more or less weakened due to the general receptivity of the matter (again, another form).
So it would seem that the principle of individualism in things is the imperfect convergence of a system of formally distinct formalities in a single form united to matter. The universal form establishing the general, containing within it the formally distinct particular inherent in matter capable of a multiplicity of influences. I.e., matter can be subject to multiple forms with their own formally distinct formalities.
BUT, this is only in the natural world. In the world of artificial objects, Ockham prevails. Every single similarity amongst artificial objects is a purely conceptual and mental reality. The universal nature of chair only exists in our mind.
But there is an analogy between Gods works and mans works. As the chair is a manifestation of certain mechanical and mathematical laws holding it together, so is the tree a manifestation of wondrously complex and detailed laws of chemical and physical reactions which constrain matter to be not only “a tree” but even “This here tree.”
But even in the world of artificial objects, each element is a composite of universal forms and essences. A Gold ring has its shape via the man, but the Gold has its being via God alone. So everything found in creation, whether natural or artificial is held in existence by God, but not everything has its own universal nature as such. Only natural objects. And this is proven by their ability to reproduce themselves not only particularly, but also generally, via those laws which make them both “this” and “this here” and not “that” and “that there.”
SCOTUS and Ockham are right in different areas.