Before moving on to Aristotle, I thought it would be helpful to review what we learned from Plato’s metaphysics.

This is the final installment in our series of Plato’s metaphysics.

Part one can be found here.

Part two can be found here.

Part three can be found here.

Why is Plato important in the development of Western metaphysics? One answer is his discovery of form or essence. The idea of essence will be developed in future posts. For now, however, the idea of essence is simply that which makes something the kind of thing it is. Essence is the “whatness” of a thing. It is usually distinguished from substance. In modern philosophical terms, substance is the foundation which underlies sensible qualities or intellectual activities. It is that which underlies or upholds the particular things of our experience.

Plato was correct to point out that things have form or essences. A cat, for example, has a certain nature and character that makes it different from a dog. If the cat, however, runs into the road, is hit by a truck, and sadly dies, it undergoes substantial change but the essence of cat does not expire. Conceptually, properties of “catness” such as chasing mice and meowing for attention perdure and are instantiated in other cats.

In a real sense, Plato’s philosophy of Forms is trying to solve the problem he inherited from the pre-Socratics. Plato realized that reality can not be simply reduced to chaos and flux as Heraclitus and Protagoras suggested. On the other hand, all reality can not be one and immutable as Parmenides argued. We must have an objective basis for reality and value judgments. Plato’s “Form philosophy” was his attempt to ground reality in an objective truth which constitutes the real essence or being of a thing.

Essences, or essential forms, are properties of all things. An essential form is simply a feature or characteristic which belongs to the nature of a thing. We can conceive of “tableness” even when I dismantle my particular table and use it for fire wood. We all have a good idea of what it means to be human or when we consider the nature of humanity.

The idea of form or essence, discovered by Plato, is one of the greatest contributions to Western metaphysics. Metaphysics is about describing the world in the most general way and trying to explain the genuine nature of the world which is the foundation of this physical world. Essence is a real property of existence or Being. Other properties of Being such as the law of noncontradiction, the axioms and principles of mathematics, and the law of causality (which is really an extension of the law of noncontradiction) are also transcendent metaphysical truths. As we will see later, Aristotle considered the categories of act and potency to be foundational metaphysical truths. The study of metaphysics really does provide knowledge about our world. In fact, these metaphysical truths makes every other field of human inquiry possible.

But does Plato really solve the problem of the one and the many? For Plato the question of the one and the many is translated into Being (the one) and Becoming (the many). Being is the transcendent world of form and Becoming is the physical world we live in every day. Today, most philosophers speak in terms of Being and Becoming but the question of the one and the many is what underlies those categories.

Plato does not stop with a simple division between Being and Becoming. As we have seen, Being is divided into mathematical forms, and then the higher forms (sometimes he calls it the Form of the Good). Becoming is also divided into images and then the higher level of sensible objects.

The problem arises, however, of how the forms of Being actually participate or interact with the realm of Becoming. Unfortunately, Plato never resolves this situation. Dividing the two realms into further realms only complicates the issue. This, unfortunately, has been a significant problem in the Platonic tradition. Plotinus tried to solve the problem with his Forms of the All-Soul, Intellectual Principle, and other forms all the way down to physical things, but the Neo-Platonism of Plotinus still confuses the matter. Adding more Forms does not help the situation. The problem occurs whenever things get divided up unnecessarily. Within the Platonic tradition, the question always remains—what is the relationship supposed to be between the Form and particular, Being and Becoming, the one and the many? Plato never answers this.

A further problem is that Plato never really addresses the problem of change. The question that needs to be answered, is when a physical thing changes, does the transcendent Form of the thing also change? Or does the Form cause the change? But then we are back to our original question of how the Forms interact or participate in physical reality.

It is also worth noting the inherent Gnosticism within the Platonic tradition. Gnosticism is the ancient philosophical and theological view which disparaged and denigrated physical reality. In Plato’s overall philosophy, the physical reality of this world mattered very little because the true reality existed in a transcendent heavenly realm of Forms. This view was even stronger with the neo-Platonist, Plotinus.

(To be fair, the middle and late Plato indicates stronger Gnostic tendencies than the early Plato. In the Charmides, for example, Plato has Socrates speak of the union between essence and matter and the error of separating these things. In regards to Plotinus, although he wrote the last part of his second Ennead as a refutation Gnosticism, his Gnosticism is clearly stronger than that of Plato’s.)

So, the story continues. If essence is a valid metaphysical principle (and it is), what is its relationship to physical reality? And how do we account for change and causation? Fortunately, there are good answers to these questions and they come from Aristotle. His metaphysical scheme is complex but the part we will examine is what has come to be known as immanent realism.