Form of Inference, fragment 2
Archival Number: A6b
Author: Lonergan, B.
Wrapper of A0006a and A0006c. Legal-size page numbered 9, seems to be a page of the typescript of ‘The Form of Inference.’
Database and descriptions © Copyright 2017 by Robert M. Doran
Enough has been said to pave the way for a discussion of syllogism. The difficulty here is the multiplicity of interpretations: to refute all of them would be maddening. The best plan seems to be to outline the correct interpretation, show hoes this necessitates hypothetical expression, and then give a general refutation of other interpretations. Syllogism is reasoning and a correct interpretation of syllogism is one which makes it clear that the premises are the reasons; interpretations that labour under some metaphysical prepossession are all biased and usually end up with syllogism working on some slot-machine principle.
Aristotle considered the middle term as giving the reason of the conclusion, and accordingly wished to reduce second and third figure syllogisms to the first figure because the middle term was more apparently the reason in the first figure than in the others. Aristotelians of the spirit will be willing to reduce the whole three figures to hypothetical form if that makes the reasons still more apparent. It does.
According to Mr Joseph’s fine analysis of syllogism , in the first two figures the middle term denotes a predicate of the subject which by its presence or absence in the subject establishes the presence or absence of another predicate; in the third figure, the middle term denotes an instance or a class of instances which go to show that some predicate may belong or need not belong to the subject. Examples are,
Darii: All pedants are mentally unbalanced;
Some few professors are pedants;
Therefore, some few professors are mentally unbalanced.
Camestres: All victims of tuberculosis are languid;
None of these boys are languid;
Therefore, none of these boys are tubercular.
Disamis: Some tea ought not be prohibited;
All tea is imported;
Therefore, some imports ought not be prohibited.
As shown by the answer to Mill’s objection against syllogism, the first example is to be deduced not from what is true of all pedants but from what is true of pedantry as such; we must proceed from the predicate ‘pedant’ to the implication of that predicate ‘mental trouble’; in other words the argument is.
Because some professors are pedants, they are mentally unbalanced. Similarly in the second case, the natural interpretation is that
The boys are not tubercular, because they are not languid.