|
13099
|
Analysing right down to primitive concepts seems beyond our powers [Leibniz]
|
|
Full Idea:
An analysis of concepts such that we can reach primitive concepts...does not seem to be within human power.
|
|
From:
Gottfried Leibniz (Introduction to a Secret Encyclopaedia [1679], C513-14), quoted by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz
|
|
A reaction:
Leibniz is nevertheless fully committed, I think, to the existence of such primitives, and is in the grip of the rationalist dream that thoughts can become completely clear, and completely well-founded.
|
|
13764
|
Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? [Edgington]
|
|
Full Idea:
Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? Are they non-truth-functional, like 'because' or 'before'? Do the values of A and B, in some cases, leave open the value of 'If A,B'?
|
|
From:
Dorothy Edgington (Conditionals [2001], 17.1)
|
|
A reaction:
I would say they are not truth-functional, because the 'if' asserts some further dependency relation that goes beyond the truth or falsity of A and B. Logical ifs, causal ifs, psychological ifs... The material conditional ⊃ is truth-functional.
|
|
13765
|
'If A,B' must entail ¬(A & ¬B); otherwise we could have A true, B false, and If A,B true, invalidating modus ponens [Edgington]
|
|
Full Idea:
If it were possible to have A true, B false, and If A,B true, it would be unsafe to infer B from A and If A,B: modus ponens would thus be invalid. Hence 'If A,B' must entail ¬(A & ¬B).
|
|
From:
Dorothy Edgington (Conditionals [2001], 17.1)
|
|
A reaction:
This is a firm defence of part of the truth-functional view of conditionals, and seems unassailable. The other parts of the truth table are open to question, though, if A is false, or they are both true.
|