Last semester, someone criticised me for doing Logic because she said it was a cop out for me since I knew a lot about it already. I dispute this. Indeed, one of the reasons I took it was, as someone said about the 'Philosophy' component in 1st year PPE, "You can do 'logic' which is, strangely enough, quite illogical". And indeed it is to varying degrees. Argh.

For example:
- The statements "all ravens are black" and "all non-black objects are non-ravens" are logically equivalent.
- If the statement "all men are mortal" is true, it does not mean that men exist
- 'If a nuclear bomb hit us, I would be the King of France.' is actually true in a true-false conditional. As a corollary, if a proposition is true, any proposition can be said to precede it in a true-false conditional, eg "If Ikea sucks, it is from Sweden" is true.
- Similarly, 'If I am a monkey's uncle, Elvis is dead' is true whether or not I am a monkey's uncle. It is only false if I am a monkey's uncle and Elvis is alive.
- If "All men are stupid", you cannot conclude that "Some men are stupid", but you can claim that "John is stupid", since the statement "John is stupid" does not mean that John exists

In any case, formal/predicate logic is useless because in real life, no serious people make arguments using the quantifiers "All", "No" or "Some" (ie At least one). Rather we argue using the quantifiers "Most" and "Some" (ie A non-negligible proportion).