● Epistemology: a theory of knowledge.
● According to Descartes, our knowledge is like a rickety building--- we need to tear it
down and start all over. Meanwhile, we need to make decisions on a day to day basis (in
the metaphor, this relates to finding somewhere else to stay).
Algorithms versus Heuristics
● An algorithm is a procedure that is guaranteed yield a solution to a given problem in a
finite number of steps, if a solution exists.
● A heuristic is a procedure that is likely to yield a solution to a given problem in a finite
number of steps, if a solution exists.
Maxims for Action
1) Obey local laws and customs, including religious customs.
2) Stick to decisions, once made
3) Focus on changing what is under your control; accept what is not
4) Choose the most suitable occupation.
Three Steps of Methodical Doubt
● Step one: the senses are sometimes deceptive. So all beliefs arrived at through the senses
can be doubted.
● Step two: reasoning is sometimes incorrect. So all beliefs arrived at by reasoning can also
● Step three: In fact, we might be dreaming--- this is a possibility we can’t rule out. So all
our beliefs can be doubted (“hyperbolic doubt”)
○ Cogito, ergo sum = “I think; the