The Twenty Four Thomist Theses

No, this is not punishment for Lent. I love Thomism, and in 1914 the Catholic Church endorsed these Twenty Four Theses as the core of Thomistic philosophy and a reliable guide for genuine philosophical insight.

These Theses are seriously Thomistic-- they are profound, employ a technical vocabulary, and require quite a bit of thought and reflection and some background familiarity with the issues and concepts involved. In other words, they are excellent philosophy. They represent the core of Thomist metaphysics, and thereby the core of Western philosophy. One of the real indictments of our educational system is that most even well-educated people don't even know these exist, let alone have any familiarity with them.

I'll try to take them one by one over a series of posts. My interpretations are of a very amateur sort, but I hope they convey some of the truth expressed in each and serve to inspire deeper reading and contemplation.

Thesis 1:

Potency and Act so divide being that whatsoever exists either is a Pure Act, or is necessarily composed of Potency and Act, as to its primordial and intrinsic principles.

The distinction between potency and act is the core of Thomist metaphysics. Act means actuality-- the aspect of something that exists that is perfect, in the sense that it is what makes it what is truly is. Potency is possibility-- potency does not exist, but it potentially exists. Being-- all that exists-- is wholly described by either act alone or potency mixed with act. 

An example of a combination of potency and act in a substance is an acorn. The act of an acorn is what it actually is: a little hard roughly round seed made of organic matter, with a shell, of a brownish-greenish color, etc. The potency of an acorn is an oak tree and all of the intermediate stages of growth of the acorn. The acorn itself is not an oak tree, but it has the potency (the potential) to become one. Potency is, in this sense, in between existence (act) and non-existence (non-being). 

Aristotle's brilliant doctrine of potency and act-- adopted by St. Thomas-- solves the ancient riddle of change in nature-- the debate as to whether change exists (Heraclitus) or is an illusion (Parmenides). Aristotle's answer is that there are three ways of delimiting existence-- actuality, potency, and non-existence. Change is the elevation of potency to act. 

In an acorn, the acorn per se is act. The oak tree is potency. And a Corvette is non-existence. An acorn is an acorn, it can be an oak tree, and it can't be a Corvette. 

Everything that exists-- God, angels, man, animals, inanimate things-- must be either Pure Act-- actual perfection without admixture of potency (possibility), or a mixture of potency and act, which is something capable of perfection, but actually in admixture of imperfection (potency) and perfection (act). The term "perfection" in Thomist metaphysics does not mean quite what the modern term perfect means. It means (in Thomism) that a substance has all of the attributes it can have, with no possibilities left unrealized. 

Only God is perfect Act. All created substances are admixtures of act and potency. 

It is a mistake to see the Thomist delineation of potency and act as metaphysical speculation unconnected to reality. Werner Heisenberg, who unlike most modern scientists actually knew something about metaphysics, famously observed that the quantum mechanical collapse of the waveform is an obvious example of reduction of potency to act. 

Centuries before modern physics, metaphysicians like Aristotle and St. Thomas laid the groundwork for an understanding of nature at its foundation.