PHLA10H3 Lecture Notes - Lecture 2: Counterexample, Deductive Reasoning, Begging
Document Summary
Why no philosophical labs: thought experiments rather than hands on stuff. Argument definition: structure of statements designed to prove some points, premises. Arguments should be short, reduce premises, and break up arguments. Arguments which are supposed to be deductively valid. If premise = true: then conclusion = true. Example: if someone lives in edmonton, then they live in canada, fred lives in edmonton, so fred lives in canada. If word valid in logic is about arguments, there are no arguments or ideas. Begging the question: conclusion is inside premises, valid argument never adds any information that is not already in premises. Counter-example: make a another version of the argument and test it out. Adding premises, invalid argument can be made into a valid argument. Premises = true, has to have a true conclusion. Debates about the quality of a deductive argument can take two forms: debate about whether the logical form is valid, debate about whether the premises are true.
