Copernicus proposes the heliocentric model to replace the geocentric model,
1543: The sun is the centre of the universe and everything revolves around it.
Thought it would simplify observation.
Galileo and Kepler discover direct evidence for the heliocentric theory, 1609 –
1612: the planets do not move in circles but in elliptical orbits. The planets speed
up and slow down as they orbit the sun. Kepler’s “laws of planetary motion” were
the basis for Newton’s theories. Galileo improved the telescope. Was put in jail
for defending the Copernican system.
A new physics is developed – nature is not purposive, the same physics applies
up there and down here – Galileo, Kepler, Descartes, and culminating with Isaac
Newton: three laws of motion and universal gravitation.
3) Describe Descartes’ main epistemological project in the Meditations, including
the role played in it by the method of doubt.
His project was to undertake a complete rational reconstruction. He wanted to
question all of his beliefs and see which ones were really true or not. The method
of doubt was a way of looking at all of your beliefs and rejecting any that were
open to doubt. By doing this, you will be left with beliefs that have no doubts at
all. These will then serve as the base for reconstructing your belief system. It isn’t
necessary to look at each belief individually, so they can be examined in groups.
4) Do you think it is actually possible to carry out Descartes’ main epistemological
project in the Meditations. Why or why not?
I do not. I think it would take too long to go through my entire belief system. Even
when grouping beliefs together, there too many small and simple beliefs such as
the sky being blue that it would take forever to sort through them. Also some
might have a bit of doubt because others have chosen not to believe it, yet there
is evidence that the belief is really true.
5) What is Descartes’ famous Cogito argument, and how convincing is it as a
response to the scepticism of Meditation 1?
One belief that can absolutely not be doubted is that he exists. By the very fact
that he doubts himself, it follows that he must exist. “I am, I exist, is necessarily
true each time that I pronounce it, or mentally conceive it.” One interpretation of
the argument is that it is an intuition. He is giving expression to a mental intuition
by which he grasps his own existence. He thinks/doubts his existence; therefore
he intuits his existence because he is thinking. People don’t like this one because
it doesn’t make sense. The second interpretation is the pragmatic interpretation.