Descartes' Project
Physics was strongly developing. He was interested in contributing to physics in the Galilean sense and therapy.
However, he found that a good, metaphysical foundation for physics was lacking* |
Archimedean Point
= the first point of certainty
according to Descartes the only thing that is certain is uncertainty. Uncertainty required the capacity to doubt
all else is built up from this one fixed point |
I think, therefore I am (cogito ergo sum)
if I'm doubting, I'm thinking
if there is something that thinks, it must exist
-> so, I must exist if I think
I am a thing that thinks (res cogitans)
-> thinking is the condition for asserting that I exist
so, "I" exist
we cannot doubt that we doubt |
Mind Body Problem
According to Descartes, the mind (res cognito) is a different substance as the body (res extensa). From this idea follows the mind-body problem, which is the problem that arises when figuring out how these two interact with each other, and there seems to be no way in which two independent substances can interact.
different forms of reality
formal reality: if we think then we have ideas
-> if something is true by existing it has a formal reality
objective reality: ideas can represent things truly or falsely
-> if something is true because it represents something that exists it has an objective reality
things can have more or less reality |
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Possibilities fo Doubt
we should doubt everything; as anything can mislead us without us knowing it
- authority of existing sources: people could lie or be wrong themselves
- senses: are not informative enough/could be optical illusions
-> we are not sure enough of what we are perceiving is real: "maybe I am dreaming?"
- mathematics: logic does not depend on sensory input (so is this real?)
- God: a being more powerful than me could mislead me
-> in short, the senses, mathematics, and Gods existence itself are not clear |
Methodological Doubt
a metaphysical foundation needs to be beyond all doubt.
methods that can lead to mistakes are not fundamental; absolute demands
cartesian doubt:
- radical: nothing is accepted as true unless it's indubitable
- methodical doubt is the method to find absolute truth |
benevolence
according to Descartes:
- God is perfect
- deceiving is imperfect; God would not deceive me and allows me to gather truth
- there is no complete scepticism
- clear and distinct ideas are true
- there is a clear idea of another substance: this other substance is extended (res extensa)
everything in the world outside of us is extended and these have parts.
when perceiving such res extensa something can go wrong, but we can correct ourselves (as God allows this)
-> God is not a deceiver and we have a clear and distinct idea of extension |
Cartesian Dualism
res cognitans: thinking substance (mind/soul)
res extensa: extended substance (body)
-> they exist independent of one another
however, the body and soul are united, even if they are different substances
a substance, according to Descartes is defined by its essential attribute; to find an attribute that is not reducible to any other, is also to find a substance defined by the attribute.
-> matter = extension. mind = thought |
Scala Naturae
Descartes claims that, Man is special because he can think, and is only in body part of this mechanical nature. Man can understand God from thought, and animals are only machines |
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the wax argument
In the wax argument, he argues that though the consistence of wax changes when it is heated, it is still the same piece of wax as it was before it was heated.
With this, he wants to prove that our senses give us conflicting reports and so it is the "intellect" that allows our mind to perceive and conclude that it is still a piece of wax.
God
according to Descartes:
We have the idea of God (formal reality). This idea is that God is the most perfect thing (objective reality)
→ Ideas are caused by existing things (formal reality) (mechanical viewpoint)
Only something that has at least as much reality as what is produced can cause something to exist.
The idea of God contains the idea of perfection: i am imperfect, so there must be something perfect with the proper amount of reality
The idea of God has to come from outside me, namely from God (highest formal reality)
And so, God exists |
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