3 ideas
| 16519 | No one can conceive of a possible substance, apart from those which God has created [Arnauld] |
| Full Idea: I am much mistaken if there is anyone who dares to say that he can conceive of a purely possible substance, …for although one talks so much of them, one never conceives them except according to the notion of those which God has created. | |
| From: Antoine Arnauld (Letters to Leibniz [1686], 1686.05.13), quoted by David Wiggins - Sameness and Substance 4.2 | |
| A reaction: This idea cashes out in the 'necessitism' of Tim Williamson, and views on the Barcan formulae in modal logic. |
| 17743 | De Morgan introduced a 'universe of discourse', to replace Boole's universe of 'all things' [De Morgan, by Walicki] |
| Full Idea: In 1846 De Morgan introduced the enormously influential notion of a possibly arbitrary and stipulated 'universe of discourse'. It replaced Boole's original - and metaphysically a bit suspect - universe of 'all things'. | |
| From: report of Augustus De Morgan (works [1846]) by Michal Walicki - Introduction to Mathematical Logic History D.1.1 | |
| A reaction: This not only brings formal logic under control, but also reflects normal talk, because there is always an explicit or implicit domain of discourse when we talk. Of virtually any conversation, you can say what it is 'about'. |
| 6457 | Sensations are mental, but sense-data could be mind-independent [Vesey] |
| Full Idea: Whereas a sensation is by definition mental, a sense-datum might be mind-independent. | |
| From: Godfrey Vesey (Collins Dictionary of Philosophy [1990], p.266) | |
| A reaction: This seems to be what Russell is getting at in 1912, as he clearly separates sense-data from sensations. Discussions of sense-data always assume they are mental, which may make them redundant - but so might making them physical. |