I'm not going to make any judgements regarding the truth values of the premises involved but I would like to say something about proper syllogistic form and the validity of the syllogisms mentioned in post 43 and 45 (for the sake of anyone who would like to learn more about syllogisms):
First of all, the sequence of the two premises needs to be reversed. The first premise (the major premise) should always contain the major term which is the predicate (second term) of the conclusion.
Thus, Plato's syllogism should read:
P1: All physical states are extended in space.
P2: All mental states are not physical states.
C: All mental states are not extended in space.
This is a valid syllogism of the form EAE-1 (known as Celarent):
E - All M are not P.
A - All S are M.
E - All S are not P.
If we change the conclusion from All to Some (O - Some S are not P, as Alglenne may have been suggesting in post 45) then we end up with a syllogism of the form EAO-1 (known as Celaront or weakend Celarent) which is conditionally valid. (It contains the existential fallacy because both premises are universal but the conclusion is particular.)