1/18/15 5:54 PM

PHIL 102

BACKGROUND

- Chapters 1-5 = Sentential Logic- Chapters 7-10 = Predicate Logic- Good deductive reasoning = Truth preserving

o All As are Bso Some Cs are As <= STANDARD FORMo ------------------o Some Cs are Bs

- Aristotelian Logic is best suited for relations among groups- Can have invalid syllogistic form

o Some As are Bso All Cs are As <= STANDARD FORM o ------------------o All Cs are Bs

- Invalid syllogistic form can have true premises and a true conclusion, but this form can also have true premises and false conclusion (which is why its invalid)

o Some positive numbers are even numberso All numbers greater than zero are positive numbers

o -----------------------------------------------------------o All numbers greater than zero are even numbers

- There are limitations to Aristotelian method, which is when we move to sentential logic

SENTENCES, TRUTH VALUES, AND ARGUMENTS

- Statements have Truth Value of (T) True or (F) False- Not all sentences are T or F (ex: commands, “Ouch”, etc)- Nor are they in standard form, can even start with conclusion and

end with premiseo Ex: Michael will not get the job, for whoever gets the job will have

strong references, and Michael’s references are not strong- Whole argument can also be buried in an ongoing text- To extract arguments from discourse look for

o Conclusion Indicator Words Therefore Thus It follows that So Hence Consequently As a result

o Premise Indicator Words Since For Because On account of Inasmuch as For the reason that

- Not every piece of discourse is intended as an argument, can just have a bunch of T or F statements with no reason to treat any of them as conclusions or premises

- An argument is a set of two or more sentences, one of which is designated as the conclusion and the others as the premises

EXERCISES

a)