4 ideas
| 15380 | Barcan:nothing comes into existence; Converse:nothing goes out; Both:domain is unchanging [Vervloesem] |
| Full Idea: Intuitively, the Barcan formula says that nothing comes into existence when moving from a possible world to an alternative world. The converse says that nothing goes out of existence. Together they say the domain of quantification is fixed for all worlds. | |
| From: Koen Vervloesem (Barcan Formulae [2010]) | |
| A reaction: Stated so clearly, they sound absurd. The sensible idea, I suppose, is that you can refer to all the things from any world, but that doesn't mean they are possible. Shades of Meinong. 'Square circles' are not possible. |
| 8417 | Direct realism is false, because defeasibility questions are essential to perceptual knowledge [Galloway] |
| Full Idea: Since awareness of defeasibility issues is an essential prerequisite for any genuine perceptual knowledge of even straightforward physical objects, any realist theory of perception must be indirect or representative, rather than direct. | |
| From: David Galloway (lectures [2007]), quoted by PG - lecture notes | |
| A reaction: [a very compressed summary] A very interesting claim. The issue might be over what direct realism is actually claiming. If it claims full-blown knowledge, then the criticism seems good. But it might survive if it claimed rather less. |
| 1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
| Full Idea: Archelaus was the first person to say that the universe is boundless. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3 |
| 5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |
| Full Idea: Archelaus wrote that life on Earth began in a primeval slime. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus | |
| A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea. |