Monty Python fans may enjoy this break from the harrowing trail of logical
positivism http://bau2.uibk.ac.at/sg/python/Scripts/HolyGrail/g-logic.html
From the album of Monty Python and the Holy Grail


Good evening. The last scene was interesting from the point of view of a
professional logician because it contained a number of logical fallacies;
that is, invalid propositional constructions and syllogistic forms, of the
type so often committed by my wife.

'All wood burns,' states Sir Bedevere. 'Therefore,' he concludes, 'all that
burns is wood.' This is, of course, pure bullshit. Universal affirmatives
can only be partially converted: all of Alma Cogan is dead, but only some of
the class of dead people are Alma Cogan. 'Oh yes,' one would think. However,
my wife does not understand this necessary limitation of the conversion of a
proposition; consequently, she does not understand me, for how can a woman
expect to appreciate a professor of logic, if the simplest cloth-eared
syllogism causes her to flounder?

For example, given the premise, 'all fish live underwater' and 'all mackerel
are fish', my wife will conclude, not that 'all mackerel live underwater',
but that 'if she buys kippers it will not rain', or that 'trout live in
trees', or even that 'I do not love her any more.' This she calls 'using her
intuition'. I call it 'crap', and it gets me very irritated because it is
not logical. 'There will be no supper tonight,' she will sometimes cry upon
my return home. 'Why not?' I will ask. 'Because I have been screwing the
milkman all day,' she will say, quite oblivious of the howling error she has
made. 'But,' I will wearily point out, 'even given that the activities of
screwing the milkman and getting supper are mutually exclusive, now that the
screwing is over, surely then, supper may now, logically, be got.' 'You
don't love me any more,' she will now often postulate. 'If you did, you
would give me one now and again, so that I would not have to rely on that
rancid Pakistani for my orgasms.' 'I will give you one after you have got me
my supper,' I now usually scream, 'but not before'-- as you understand,
making her bang contingent on the arrival of my supper. 'God, you turn me on
when you're angry, you ancient brute!' she now mysteriously deduces, forcing
her sweetly throbbing tongue down my throat. 'Fuck supper!' I now invariably
conclude, throwing logic somewhat joyously to the four winds, and so we
thrash about on our milk-stained floor, transported by animal passion, until
we sink back, exhausted, onto the cartons of yogurt.

I'm afraid I seem to have strayed somewhat from my original brief. But in a
nutshell: sex is more fun than logic-- one cannot prove this, but it 'is' in
the same sense that Mount Everest 'is', or that Alma Cogan 'isn't'.