98

Logic 98

from obervation of creations of our own visual imagination which we may set down on paper in terms of diagrams.
When it comes to logical truth I do not think the intuition is quite what Lange describes it.
He holds that we imagine something like an Euler's diagram but I do not think that necessary.
There are other ways as I shall show among which we may take our choice.
Lange holds up as a model Aristotle's proof of tehe convension of the universal negative proposition.
As well as I can translate Aristotle's untranslatable language his proof reads as follows:

"If to none of the Bs the [designation] A belongs; neither will the [designation] B belong to any of the As.
For if to any as for example to C it will not be true that none of the Bs the [designation] A belongs.
For C is one of the Bs"

It seems to me it would be much simpler to say that if No B is A but some A is B then we should have the two premisses of a syllogism in Ferio from which