PHIL 1102 Lecture Notes - Lecture 6: Categorical Proposition, Obversion, George Boole
Document Summary
Key contradictory propositions at this stage are a-o and e-i. If some s are p, then it is false that all s are not p. but if some s are p is false, this is just to say that no s are p. I woke up at 7am this morning and i woke up at 8am this morning these could both be false but cannot both be true. Some cats are brown and some cats are not brown. Any cat is either brown or not brown, so it can"t be that both of these are false (note, due to some, there is at least one cat). Immediate arguments are arguments with a single premise. An argument by conversion is an argument made by permuting the subject and predicate terms of a categorical proposition. No s are p, therefore no p are s. only valid for full affirmative or negative (all/none)
