Substance Dualism

Classification

Position level

specific

Domains

Metaphysics, Philosophy of Mind

Overview

In the Sixth Meditation, Descartes argued that mind and body can be clearly and distinctly conceived apart, that God can make apart whatever can be so conceived, and that what can exist apart are distinct substances. Mind is essentially thinking and unextended, body essentially extended and unthinking, and neither is made out of the other.

The problem is what remains once they are separated: how an unextended thinking substance and an extended physical one act on each other at all. Elisabeth of Bohemia put the objection to Descartes in his own lifetime and never received a satisfying answer, and it remains the position's central liability, because causal traffic between the two is precisely what the theory has to preserve.

Position on

• How Many Fundamental Substances?

  On this question, substance dualism counts two fundamental kinds of created substance—thinking minds and extended bodies—rather than only two individual substances.

• The Mind–Body Problem

Held by traditions

• Platonism

  The arguments are Plato's own, in the Phaedo, Meno and Phaedrus; later Platonist accounts of the soul descend from them.

  Question scope: The Mind–Body Problem

Broader position

• Mind–Body Dualism

Rival positions

• Leibnizian Substance Pluralism

  Question scope: How Many Fundamental Substances?

• Physicalism

  Question scope: The Mind–Body Problem

• Spinozistic Substance Monism

  Question scope: How Many Fundamental Substances?

References

• Stanford Encyclopedia of Philosophy, Dualism
• René Descartes, Meditations on First Philosophy (1641), Sixth Meditation, AT VII 78 (what can be clearly and distinctly understood apart can be made apart by God, so mind and body are really distinct); the Preface, AT VII 7–8, denies that the doubt of the Second Meditation proves it
• Stanford Encyclopedia of Philosophy, Substance, §2.4 (Descartes recognizes mental and material created substances as two kinds)