Philosophical Works · Chapter
LIII explained
Descartes explains that each substance has one principal attribute that constitutes its nature: thought for the mind and extension for the body.
What happens
Descartes explains that each substance has one principal attribute that constitutes its nature: thought for the mind and extension for the body. All other properties are merely modes of these primary attributes.
Free preview opens on this chapter — companions, themes, and character notes appear beside the text.
Narrative arc
Story tension across the book — this chapter sits in Exposition.
- Setup
- Escalation
- Breaking point
- Aftermath
- Closing
This passage marks the story's dramatic climax because it presents the precise moment of epistemological crisi…
Full beat labels and climax notes unlock in the reader.
Follow the arc while readingThemes in this chapter
- Mind-Body Dualism
The chapter explicitly distinguishes mind (thinking substance) from body (extended substance) by their principal attributes.
Characters to notice
- Narrator
The narrator presents the argument that each substance has a principal attribute.
Key passages
“That of every substance there is one principal attribute, as thinking of the mind, extension of the body.”
Every substance has a single defining attribute: thought for the mind, extension for the body.
This establishes the core dualist principle.
“Thus, extension in length, breadth, and depth, constitutes the nature of corporeal substance; and thought the nature of thinking substance.”
The essence of physical substance is extension in three dimensions, while the essence of mental substance is thought.
Clarifies the distinct essences of mind and body.
