Combining Texts

Ideas for 'Confessions', 'On Fate ('De fato')' and 'Summa totius logicae'

unexpand these ideas     |    start again     |     choose another area for these texts

display all the ideas for this combination of texts


2 ideas

5. Theory of Logic / D. Assumptions for Logic / 1. Bivalence
How can the not-true fail to be false, or the not-false fail to be true? [Cicero]
     Full Idea: How can something that is not true not be false, or how can something that is not false not be true?
     From: M. Tullius Cicero (On Fate ('De fato') [c.44 BCE], 16.38)
     A reaction: We must at least distinguish between whether the contrary thing is not actually true, or whether we are prepared to assert that it is not true. The disjunction may seem to be a false dichotomy. 'He isn't good' may not entail 'he is evil'.
5. Theory of Logic / G. Quantification / 1. Quantification
The word 'every' only signifies when added to a term such as 'man', referring to all men [William of Ockham]
     Full Idea: The syncategorematic word 'every' does not signify any fixed thing, but when added to 'man' it makes the term 'man' stand for all men actually.
     From: William of Ockham (Summa totius logicae [1323], I.c.iv)
     A reaction: Although quantifiers may have become a part of formal logic with Frege, their importance is seen from Aristotle onwards, and it is clearly a key part of William's understanding of logic.