4312 | To understand a phenomenon, we must understand why it is necessary, not merely contingent [Spinoza, by Cottingham] |
5484 | Essentialists don't infer from some to all, but from essences to necessary behaviour [Ellis] |
15558 | A good explanation is supposed to show that the event had to happen [Lewis] |
16812 | An explanation shows why it was necessary that the effect occurred [Lipton] |
17938 | Mathematics can show why some surprising events have to occur [Colyvan] |