5 ideas
19404 | Necessities rest on contradiction, and contingencies on sufficient reason [Leibniz] |
Full Idea: The principle of contradiction is the principle of necessity, and the principle that a sufficient reason must be given is the principle of contingency. | |
From: Gottfried Leibniz (On Sufficient Reason [1686], p.95) | |
A reaction: [this paragraph is actually undated] Contradictions occur in concrete actuality, as well as in theories and formal systems. If so, then there are necessities in nature. Are they discoverable a posteriori? Leibniz says not. |
6349 | I can prove a hand exists, by holding one up, pointing to it, and saying 'here is one hand' [Moore,GE] |
Full Idea: I can prove now that two human hands exist. How? By holding up my two hands, and saying, as I make a certain gesture with the right hand, 'Here is one hand', and adding, as I gesture with the left, 'and here is another'. | |
From: G.E. Moore (Proof of an External World [1939], p.1) | |
A reaction: The words need to be spoken, presumably, so that what he is doing fits into the linguistic conventions of what will normally be accepted as a proof. In fact, just holding the hand up seems enough. The proof begs the question of virtual reality. |
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 |
19403 | Each of the infinite possible worlds has its own laws, and the individuals contain those laws [Leibniz] |
Full Idea: As there are an infinity of possible worlds, there are also an infinity of laws, some proper to one, another to another, and each possible individual of any world contains in its own notion the laws of its world. | |
From: Gottfried Leibniz (On Sufficient Reason [1686], p.95) | |
A reaction: Hence Leibniz is not really a scientific essentialist, in that he doesn't think the laws arise out of the nature of the matter consituting the world. I wonder if the primitive matter of bodies which attaches to the monads is the same in each world? |
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. |