Wojtek Sokolowski wrote: > At 04:31 PM 4/20/99 -0400, you wrote: > > >> Yes it does by modus todus. If P then Q. ~P so ~ Q. If bombing > >leads to > >the destruction of Kosovo then not bombing will lead to not > >destroying > >Kosovo. > > > Modus tollens, I presume which takes the form if p then q, not q, therefore > not p. It is clear form the truth table for the implication > > > p q if p then q > T T T > F T T > T F F > F F T > > (in plain English: implication cannot lead from a true premise toa false > conclusion). > > the form "if p then q, not p therefore not q" is a non-sequitur which can > be easily demonstrated by the following example. > > If someone is shot in the head, that someone is dead. (true) > Nixon was not shot in the head. (true) > Ergo: Nixon is not dead (false). > Right. Which is why I work in a kitchen and not a classroom! The proper form of the argument would have been negation introduction or reductio ad absurdum: p ----- q ~q ----- ~p Sam Pawlett
