4 ideas
21963 | It is possible that an omnipotent God might make one and two fail to equal three [Descartes] |
Full Idea: Since every basic truth depends on God's omnipotence, I would not dare to say that God cannot make it....that one and two should not be three. | |
From: René Descartes (Letters to Antoine Arnauld [1645]), quoted by A.W. Moore - The Evolution of Modern Metaphysics 01.3 | |
A reaction: An unusual view. Most people would say that if Descartes can doubt something that simple, he should also doubt his reasons for believing in God's existence. |
6408 | Russell needed three extra axioms to reduce maths to logic: infinity, choice and reducibility [Grayling] |
Full Idea: In order to deduce the theorems of mathematics from purely logical axioms, Russell had to add three new axioms to those of standards logic, which were: the axiom of infinity, the axiom of choice, and the axiom of reducibility. | |
From: A.C. Grayling (Russell [1996], Ch.2) | |
A reaction: The third one was adopted to avoid his 'barber' paradox, but many thinkers do not accept it. The interesting question is why anyone would 'accept' or 'reject' an axiom. |
6414 | Two propositions might seem self-evident, but contradict one another [Grayling] |
Full Idea: Two propositions might contradict each other despite appearing self-evident when considered separately. | |
From: A.C. Grayling (Russell [1996], Ch.2) | |
A reaction: Russell's proposal (Idea 5416) is important here, that self-evidence comes in degrees. If self-evidence was all-or-nothing, Grayling's point would be a major problem, but it isn't. Bonjour explores the idea more fully (e.g. Idea 3704) |
23996 | Akrasia is intelligible in hindsight, when we revisit our previous emotions [Blackburn] |
Full Idea: To make my emotion intelligible [in a weakness of will case] is to look back and recognise that my emotions and dispositions were not quite as I had taken them to be. It is quite useless in such a case to invoke a blanket diagnosis of 'irrationality'. | |
From: Simon Blackburn (Ruling Passions [1998], p.191) | |
A reaction: So Blackburn rejects the idea of akrasia, because there was never really a conflict. He says rational people always aim to maximise their utility (p.135), and if their own act surprises them, it is just a failure to understand their own rationality. |