6 ideas
| 13007 | Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz] |
| Full Idea: Archimedes gave a sort of definition of 'straight line' when he said it is the shortest line between two points. | |
| From: report of Archimedes (fragments/reports [c.240 BCE]) by Gottfried Leibniz - New Essays on Human Understanding 4.13 | |
| A reaction: Commentators observe that this reduces the purity of the original Euclidean axioms, because it involves distance and measurement, which are absent from the purest geometry. |
| 16634 | I can't be unaware of anything which is in me [Descartes] |
| Full Idea: Nothing can be in me of which I am entirely unaware. | |
| From: René Descartes (Reply to First Objections [1641]), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 08.4 | |
| A reaction: This I take to be a place where Descartes is utterly and catastrophically wrong. Until you grasp the utter falseness of this thought, the possibility of you (dear reader) understanding human beings is zero. Here 'I' obviously means his mind. |
| 3635 | Essence must be known before we discuss existence [Descartes] |
| Full Idea: According to the laws of true logic, we must never ask about the existence of anything until we first understand its essence. | |
| From: René Descartes (Reply to First Objections [1641], 108) |
| 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. |
| 3634 | We can't prove a first cause from our inability to grasp infinity [Descartes] |
| Full Idea: My inability to grasp an infinite chain of successive causes without a first cause does not entail that there must be a first cause, just as my inability to grasp infinite divisibility of finite things does not make that impossible. | |
| From: René Descartes (Reply to First Objections [1641], 106) |