Descartes on Mind and Matter (16-Oct-2003)
- Recap: Aristotle says that the fundamental thing in the universe is
substance - there are many different substances in the world, each
having various properties such as size, position, colour, etc..
- Descartes also thinks that substances are fundamental, but thinks that
there are only three different types of substance:
- God, the primary substance, who has created
- Matter, and
- Mind
- Like Aristotle, Descartes thinks that substances have properties, but
that there is a principal property, which is responsible for all the
others.
- Matter is what physical objects are made from. The principal
property of matter is extension, which means the way it is arranged in
different sized lumps in various places to make the physical objects that are
in the world. If it didn't have extension, matter would not exist.
- The principal property of mind is thought: without thought, there
could be no mind.
- "Properties" of matter such as colour, smell and sound are simply aspects
of our perception of matter, not inherent properties of the matter itself.
Our experience of an object is a thought - and therefore an
aspect of mind - which is distinct from the object itself.
- Descartes' scheme of splitting the world into either mind or matter is
called dualism. Sometimes it's easy, but sometimes it's hard, to
tell what kind of substance a thing is:
- A tree
- A memory
- Kate Bush record (physical object, move about, open; pictures on the
front; LP inside; grooves; music - what's that?)
- Two issues arise with this view:
- Is it always possible to place a given substance into one or the other
category?
- How can it be that material substance can influence, and be influenced
by, mind?