What Are the Key Concepts In the Physicalism/Dualism Debate?

Post Author: Bill Pratt

Physicalism affirms the existence of the body and denies the existence of the mind or soul, while dualism affirms the existence of both the body and the soul.  Before we get into the arguments for dualism and against physicalism, we need to define some terms.

Philosopher J. P. Moreland, in the book Beyond Death, defines three key terms: substance, property, and event.  First, we look at the nature of a substance.  According to Moreland, “A substance is an entity like an apple, an acorn, a leaf, a carbon atom, a dog, or an angel.  Substances have a number of important characteristics.”

The characteristics of substances are as follows:

  1. “Substances are particular, individual things.  A substance . . . cannot be in more than one place at the same time.”
  2. “A substance is a continuant – it can change by gaining new properties and losing old ones, yet it remains the same thing throughout the change.”  For example, a leaf can change color from red to green, but it still remains the same substance, the same leaf.
  3. “Third, substances are basic, fundamental existents.  They are not in other things or had by other things.”  For example, our cat, Lily, is not in or had by something more basic than herself; she is a basic existent. 
  4. “Fourth, substances are unities of parts, properties, and capacities.”  Lily, as a substance, has properties such as grayness and fatness (we’ve had her on diet, but she’s still pretty fat).  She has parts such as four legs and a tail.  She has capacities that are not always being actualized, like the capacity to purr.  As a substance, Lily is a unity of all these things.
  5. Finally, substances have causal powers.  Lily can do things in the world, such as meowing or scratching.

The second key term is property.  “A property is an existent reality, examples of which are brownness, triangularity, hardness, wisdom, painfulness.  As with substances, properties have a number of important features.”

  1. “A property is a universal that can be in more than one thing at the same time.  Redness can be in a flag, a coat, and an apple at once.”
  2. Properties are immutable.  “When a leaf goes from green to red, the leaf changes by losing an old property and gaining a new one.  But the property of redness does not change and become the property of greenness.  Properties can come and go, but they do not change in their internal constitution or nature.”
  3. Properties are generally in or had by “other things more basic than themselves. . . . For example, redness is in the apple.  The apple has the redness.  One does not find redness existing all by itself. . . . Substances have properties; properties are had by substances.”

The third key term is event.  “Examples of events are a flash of lightning, the dropping of a ball, the having of a thought, the change of a leaf, and the continued possession of sweetness by an apple (this would be a series of events).  Events are states or changes of states of substances.  An event is the coming or going of a property in a substance at a particular time, or the continued possession of a property by a substance throughout a time.”

Now that we have substances, properties, and events clarified, we can move on to an examination of the physicalist and dualist positions.

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