This week, philosopher J.P. Moreland joins host Pat Flynn to discuss one of the most important questions in philosophy: What are we, really?

Are we just physical bodies made of parts, or is there something deeper that makes us who we are — like a soul? Their conversation challenges the popular physicalist view (we are just bodies). They make a case that human beings are unified, immaterial substances.

The problem with our being just “parts”

They begin by discussing a concept called mereological essentialism, which means that things are just collections of parts. According to this view, people are like machines or piles of matter — if you change the parts, you change the thing. Moreland pointed out that when this view is applied to people, serious problems result. Our bodies constantly change as cells die and regenerate. If we’re only our parts, how can we remain the same person over time?

What are substances?

In response, Moreland turns to an older philosophical idea: the concept of a substance. Unlike an aggregate (a pile of wood, for example), a substance is a unified whole. It exists as a single thing. A deeper unity allows it to stay the same even as it changes in minor ways.

A human being, in this view, is a substance. Your soul is the organizing principle that gives you identity and holds everything together — even when your body changes. Moreland explains that the parts of a substance are inseparable; they only exist as part of the whole. For example, a hand that’s been cut off is no longer a real hand because it has lost its role and function.

This idea goes all the way back to Aristotle (384–322 BC). He said that substances are more basic than their parts. Your identity doesn’t come from the combination of your parts — it’s your identity as a substance that gives your parts their meaning and function.

The soul vs. the mind

Moreland makes an important distinction between the soul and the mind. The mind, in his view, is just one faculty of the soul. It includes the powers to think, form beliefs, and understand logic. But the soul as a whole is more than just thoughts andbeliefs — it’s what makes you a person in the first place. It holds together all the different parts of you into a single, unified self.

A blueprint for the body

Interestingly, Moreland also compares the soul to a kind of blueprint or information system. Just as a computer program tells a machine what to do, the soul contains the information needed to build and guide the body. It tells one part to grow eyes, another to form hands, and so on. This organizing power is not found in the body alone. It comes from the soul, which directs the physical processes of the body toward specific goals.

Moreland suggests that this power sounds a lot like what scientists now call information. This non-physical information seems to be present throughout the whole body and plays a major role in development and function — something physicalism struggles to explain.

Why these concepts matter

The physicalist claims that everything about us can be explained by biology, chemistry, and physics. But as Moreland pointed out, this view leaves out important parts of reality. It can’t explain how we remain the same person over time, how reasoning works, or even how science itself makes sense. Scientific thinking assumes that there are real, stable natures to things — like electrons or gravity — and that we can study them using reason and logic. But those tools don’t come from neurons firing in the brain. They come from something deeper.

In the end, Moreland argues that the best explanation of who we are is that we are souls — immaterial, unified beings that give order and purpose to our physical bodies. This classical view, supported by both Aristotle and later thinkers, offers a clearer and more complete understanding of the human person than physicalism or any form of materialism ever can.