Cartesian Substance Dualism Lecture
Ancient Perspectives: Epicureanism and Substance Monism
Epicurus' View of the Soul: Epicurus held the position that the soul is a wholly material object. He believed it was composed of the same types of atoms and elements that constitute the rest of the material world. This view is categorized as both substance monism and property monism.
Substance Monism: This is the ontological claim that there is only one kind of substance in existence. In Epicurus' view, everything is made of the same physical atoms.
Property Monism: This is the claim that there is only one kind of property. Mind and body are considered the same thing because they share the same material properties.
Defining "Soul" in Ancient Philosophy: In this context, "soul" is used as a translation for psyche. It refers to the mind, consciousness, or intellect. Epicurus' use of the term does not carry the dualist or supernatural implications often found in later religious or popular usage.
The Linguistic Variations of the Term "Soul"
Contextual Differences in English: The word "soul" has varied meanings that are distinct from the narrow philosophical definition of "intellect" or "mind."
Soul as Person: In some historical contexts, such as ancient Russia, the term was used to count individuals (e.g., "12 souls live on this land," referring to hardworking serfs).
Soul as Emotional Depth: In popular culture, such as the lyrics of Bob Seger ("Today's music ain't got the same soul"), it refers to deep emotional feeling or authenticity.
Soul in Religious/Moral Contexts: St. Climicus writes of the "dirt and deformity of the soul" being scrubbed away, referring to a spiritual or moral center rather than the purely cognitive intellect.
Soul as Corporate Essence: A modern colloquialism, used by people such as a "millennial guy" observing Starbucks, suggests a company might "lose its soul," referencing its original identity or authenticity.
Philosophical Clarification: When historical philosophers of mind use the term "soul," they are almost exclusively speaking about the intellect or the mind. Their claims are not intended to address religion, music, or corporate authenticity.
Aristotelian Hylomorphism and Property Dualism
Aristotle’s Definition: Aristotle defined the soul as the "form of the living body."
Ontological Classification: Aristotle's view is described as substance monism combined with property dualism.
Substance Monism: There is only one substance.
Property Dualism: There are two distinct properties—the property of being a soul and the property of being a body—which belong to that single substance.
The Statue Analogy: Aristotle explains the soul-body relationship through the analogy of a statue, such as the Statue of Liberty.
Material Cause: The bronze that composes the statue corresponds to the body.
Formal Cause: The image or shape of the statue corresponds to the soul.
Hylomorphism: This term describes Aristotle's framework where beings are compounds of matter (hyle) and form (morphe).
Historical Influence: Aristotle's views were highly influential during the Middle Ages, particularly among:
Avaros (Ibn Rushd): An Islamic thinker who argued that the body is a necessary condition for the soul.
St. Thomas Aquinas: A Christian thinker who utilized Aristotle's framework to argue that a physical resurrection is necessary for a person to survive death.
Platonic Substance Dualism
The Nature of the Soul: For Plato, the soul is a simple, divine, immutable, and eternal substance.
Substance Dualism Defined: This is the view that the mind and the body are two completely independent substances. This entails property dualism as well.
The Goal of Philosophy: Plato asserted that the aim of philosophy is to separate the immortal soul (the rational intellect) from the mortal body. This is achieved through the contemplation of eternal truths as a form of preparation for death.
Distinctions between Soul and Body in Plato:
The soul rules and leads; the body follows.
The soul is immutable (unchangeable); the body is subject to change.
The body is viewed as a hindrance to the wisdom and morality of the soul.
The soul exists in the "realm of the forms" prior to entering the body and continues to exist after the body dies.
Cartesian Substance Dualism and the Meditations
Rene Descartes’ Framework: Writing in his Meditations during the 1600s, Descartes revived a form of substance dualism similar to Plato's.
Interactionism: While Descartes believed the mind is a distinct substance from the body, he maintained that the two substances causally interact with one another.
Core Logic of the Mind-Body Distinction:
Argument from Certainty: Descartes is certain that he possesses a mind, but he can doubt that he has a body (due to the possibility of being deceived by an "evil demon"). Therefore, the mind is not the body.
Argument from Conceivability: One can conceive of the mind existing without the body. If it is conceivable, then it is possible for the mind to exist without the body. If one can exist without the other, they cannot be the same thing.
Essential vs. Accidental Properties: It is impossible for a mind to exist without thinking; thought is the essence of being a mind. Conversely, it is possible for a body to exist without thinking (e.g., a corpse or a physical object like a book). Since thinking is essential to the mind but not the body, they are distinct.
Arguments for the Distinctness of Mind and Body
Argument 5 from King’s Book (The Immateriality Argument):
I am possibly immaterial.
If anything is actually material, it is essentially material.
If something is possibly not $X$, it is not essentially $X$. (If I am possibly not material, I am not essentially material).
Therefore, I am not essentially material (from 1 and 3).
Therefore, I am not material at all.
Conceivability Critique: One might question if being able to imagine oneself without a body genuinely implies that such a state is actually possible.
Modern Logical Reformulations for Dualism
Reductio ad Absurdum Argument:
Assume for the sake of contradiction: I am identical with this body.
Principle of the Necessity of Identity: If , then necessarily (). This was proven in the 20th century by Ruth Barker Marcus and Saul Crimpey. Identical objects must be identical in all possible worlds.
There is a possible world in which I am not identical with this body (it is conceivable/possible for them to be separate).
Therefore, it is not necessary that I am identical with this body.
Contradiction: Step 4 contradicts step 2 (given the assumption in step 1).
Conclusion: I am not identical with this body.
Leibniz’s Mechanical Brain Analogy
The Mill Analogy: Leibniz proposed that if we imagined the brain as a giant machine (like a mill) and could walk inside it, we would only see mechanical parts pushing against each other.
Argument Against Physicalism:
The most basic physical substances do not possess mentality.
No interaction of non-mental parts can give rise to a whole that possesses mentality.
Human beings have mentality.
Therefore, humans are not composed of physical substance.
Problems for Substance Dualism: Causal Interaction
Princess Elizabeth of Bohemia's Critique: Elizabeth challenged Descartes to explain how a human mind, being only a "thinking substance" (non-physical), can determine bodily actions.
The Interaction Paradox: If two things are distinct and independent substances, they should not depend on one another. However, the mind clearly depends on the body and vice versa. Causal interaction—how the non-physical moves the physical—remains a significant and difficult answer for dualists today.
Jaegwon Kim’s Pairing Problem
The Lack of Physical Relations: Jaguan Kim (referred to in the context as Jaguan Kim) argues that Cartesian souls do not stand in physical relations, such as being located in space and time or exerting gravitational or electromagnetic forces.
The Lack of Non-physical Relations: Conversely, brains (if they are purely physical) do not stand in non-physical relations; they do not conceive, think, or conclude.
The Problem of Pairing: Imagine two Cartesian souls, $A$ and $B$, which are qualitative duplicates. Both experience a decision to move an arm. When a physical object, $C$ (an arm), moves, there is no explanation for why Soul $A$ caused the movement and not Soul $B$.
There is no spatial relation to link Soul $A$ to Body $C$ instead of Soul $B$.
This raises the question: Why isn't there telekinesis? Why can a mind move its specific body but not another's?
Physicalist vs. Dualist Explanations: Physicalists argue the mind is simply the brain. Dualists must argue the soul is "attached" to a specific brain, but the nature of this "attachment" is difficult to define without spatial/physical terms.
Distinguishing Substance Dualism from Property Dualism
Core Definitions:
Substance Dualism: Two distinct, independent substances/objects exist.
Property Dualism: Only one substance exists, but it has two distinct properties (natures).
Functional Distinction: To avoid purely grammatical or linguistic distinctions (i.e., treating it as a difference between nouns and adjectives), the distinction should be framed in terms of dependency:
Substance Dualist: Holds that the mind is independent of any physical basis.
Property Dualist: Holds that the mind is dependent on a physical basis but possesses a distinct nature.
Ontological Goal: Philosophers seek to find "cuts in the world" (how things fundamentally are) rather than mere "cuts in our language."