René Descartes (1596-1650) was a French philosopher and mathematician known as "the Father of Modern Philosophy." He developed several philosophical systems that questioned knowledge derived from authority and emphasized the importance of methodological doubt and reason. Some of his most influential works included Discourse on the Method (1637), Meditations on First Philosophy (1641), and Passions of the Soul (1649). In these works, he established the foundations of modern Western philosophy and influential concepts like mind-body dualism, methodological skepticism, and the ontological argument for God's existence.

1. René Descartes!
(1596 - 1650)!
“The Father of
Modern Philosophy”"

2. “There are only six simple and
primitive passions, i.e. wonder, love,
hatred, desire, joy, and sadness. All
the others are composed of some of
these six, or are species of them.”
René Descartes, On the
Passions of the Soul (1649)"

3. Discourse on the
Method (1637)

4. Meditations on
First Philosophy
(1641)

5. methodological skepticism
1. If there are propositions that can potentially
be false, then we should temporarily
assume that they are false."
2. We should accept as true only those
propositions of which we can have
absolute certainty."
3. The propositions of which we have
absolute certainty should become the
foundation of our knowledge."

6. knowledge"

7. Andreas Vesalius
Galen (129 – 199)!
(1514 – 1564)"

9. Reading from
Galen, early
1500s"

11. knowledge"

12. Meditation I!
“Of The Things of Which
We May Have Doubt”"

13. “adventitious knowledge”
Knowledge acquired
through the senses."

14. “clear and distinct knowledge”
Knowledge that cannot be
doubted."

15. “dualism”

16. Meditation II!
“Of the Nature of the Human
Mind; and That It Is More
Easily Known Than the Body”"

17. “The Wax Argument”

18. How do we recognize a piece of wax?!
! By its touch."
! By its shape."
! By its color."
! By its temperature."
We recognize wax by the features
we learn through our senses.
!

19. The sensory features of wax can change.!
! Wax can change shape."
! Wax can feel different."
! Wax can change color."
! Wax can change
temperature."
Yet we still recognize that it is the
same wax. !

20. 1. The features of wax that we
experience through our senses can
change."
2. If a piece of wax changes its
features, we can still identify it as
the same piece of wax."
3. Therefore, the identity of the wax is
determined by something other
than its sensory features."

21. 1. The brain is responsible for
processing sensory information."
2. Therefore, the brain is not
responsible for our ability to
identify wax."
3. The mind is responsible for our
ability to identify wax."

22. “mind/body dichotomy”!

23. “But what then am I? A
thinking thing.”

24. a priori knowledge: independent of
empirical experience!
a posteriori knowledge: dependent
on empirical experience

25. Meditation III!
“Of God: That He Exists”"

26. Ontological Argument
An argument that tries to prove
the existence of God through
intuition and reason alone (not
through empirical means)."

27. Ontological Argument!
1. God is, by definition, the greatest
conceivable being."
2. An existent being is greater than
a non-existent being."
3. Therefore God, by definition,
exists."

28. Descartes’s Ontological Argument!
“Certainly, the idea of God, or a
supremely perfect being, is one
that I find within me just as
surely as the idea of any shape or
number.” [Meditation V]"

29. Descartes’s Ontological Argument!
“From the fact alone that I cannot
conceive of God except as existing,
it follows that existence is
inseparable from him, and
consequently that he does, in truth,
exist.” [Meditation V]"

30. 1. It is impossible to conceive of a
circle except as round."
2. It is impossible to conceive of the
number 2 except as an even
number."
3. It is impossible to conceive of God
except as a perfect being."

31. 1. God is a perfect being."
2. A necessary being is more perfect
than an unnecessary being."
3. An existent being is more perfect
than a non-existent being."
4. Therefore, God necessarily exists."

32. Isaac Newton"
(1643 - 1727)!