Carl Gustav Hempel: 2 ideas and puzzles worth knowing

2 ideas and puzzles from Carl Gustav Hempel, each explained in a minute and credited to the original work. Free on Savvy.

Seeing a red apple is technically evidence that all ravens are black
'All ravens are black' logically means the same thing as 'everything that isn't black isn't a raven.' So spotting a red apple — a non-black non-raven — counts as a tiny piece of co…
— Carl Gustav Hempel, Studies in the Logic of Confirmation
Finding a green apple is, logically, evidence that all ravens are black. How can that be?
The statement 'all ravens are black' is logically equivalent to 'everything that is not black is not a raven.' Carl Hempel pointed out that if observing a black raven counts as evi…
— Carl Gustav Hempel, Studies in the Logic of Confirmation

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