| 17209 | A thing is contingent if nothing in its essence determines whether or not it exists [Spinoza] |
| Full Idea: I call individual things contingent in so far as we discover nothing, whilst we attend to their essence alone, which necessarily posits their existence or which necessarily excludes it. | |
| From: Baruch de Spinoza (The Ethics [1675], IV Def 3) | |
| A reaction: So something could have an essence which determined that it could not exist, which is presumably a contradiction. That's a very strange sort of essence. Presumably all intrinsically contradictory essences are in some way the same. |
| 5039 | If non-existents are possible, their existence would replace what now exists, which cannot therefore be necessary [Leibniz] |
| Full Idea: If certain possibles never exist, then existing things are not always necessary; otherwise it would be impossible for other things to exist instead of them, and so all things that never exist would be impossible. | |
| From: Gottfried Leibniz (On Freedom [1689], p.106) | |
| A reaction: A neat argument, though it is not self-evident that when possibles came into existence they would have to replace what is already there. Can't something be possible, but only in another world, because this one is already booked? |
| 16986 | That there might have been unicorns is false; we don't know the circumstances for unicorns [Kripke] |
| Full Idea: I think it is not the case that there might have been unicorns. I wouldn't say it is necessary that there are no unicorns, but that we just can't say under what circumstances there would have been unicorns. | |
| From: Saul A. Kripke (Naming and Necessity lectures [1970], Lecture 1) | |
| A reaction: His point seems to be that unicorns are insufficiently individuated by the legends, whereas a typical sample of an actual creature contains everything that will individuate the species. |
| 17590 | A merely possible object clearly isn't there, so that is a defective notion [Inwagen] |
| Full Idea: The notion of a merely possible object is an even more defective notion than the notion of a borderline object; after all, a merely possible object is an object that definitely isn't there. | |
| From: Peter van Inwagen (Material Beings [1990], 19) |
| 17591 | Merely possible objects must be consistent properties, or haecceities [Inwagen] |
| Full Idea: Talk of merely possible objects may be redeemed in either maximally consistent sets of properties or in haecceities. | |
| From: Peter van Inwagen (Material Beings [1990], 19) |
| 18925 | If talking donkeys are possible, something exists which could be a talking donkey [Williamson, by Cameron] |
| Full Idea: Williamson's view on modality is that everything that could exist does exist: since there could exist a talking donkey there actually exists some thing that could be a talking donkey. | |
| From: report of Timothy Williamson (Modal Logic as Metaphysics [2013], n20) by Ross P. Cameron - Truthmaking for Presentists n20 | |
| A reaction: Well that thing certainly isn't me, or Tim Williamson. I'm guessing that the thing is an actual donkey, probably a rather bright one. Actually, I think this is one of those views that invites the incredulous stare. (Barcan formulae). |
| 15142 | Our ability to count objects across possibilities favours the Barcan formulas [Williamson] |
| Full Idea: Consideration of our ability to count objects across possibilities strongly favour both the Barcan formula and its converse. | |
| From: Timothy Williamson (Truthmakers and Converse Barcan Formula [1999], §3) | |
| A reaction: I'm not sure that I can understand counting objects across possibilities. The objects themselves are possibilia, and possibilia seem to include unknowns. The unexpected is highly possible. |
| 13719 | Barcan Formula problem: there might have been a ghost, despite nothing existing which could be a ghost [Sider] |
| Full Idea: A problem with the Barcan Formula is it might be possible for there to exist a ghost, even though there in fact exists nothing that could be a ghost. There could have existed some 'extra' thing which could be a ghost. | |
| From: Theodore Sider (Logic for Philosophy [2010], 9.5.2) | |
| A reaction: Thus when we make modal claims, do they only refer to what actually exists, or is specified in our initial domain? Can a claim enlarge the domain? Are domains 'variable'? Simple claims about what might have existed seem to be a problem. |
| 19037 | Are there possible objects which nothing has ever had the potentiality to produce? [Vetter] |
| Full Idea: Is it not possible that there be objects with (natural) properties that no actual thing ever had the potentiality to have, to produce, or constitute? (Call such properties 'super-alien properties'). | |
| From: Barbara Vetter (Potentiality [2015], 7.5) | |
| A reaction: This is a problem for her potentiality account of possibility. Her solution is (roughly) to either deny the super-aliens, or have chains of iterated possibility which take this case back to actuality. That sounds OK to me. |