display all the ideas for this combination of texts
4 ideas
12985 | Maybe motion is definable as 'change of place' [Leibniz] |
Full Idea: I believe 'motion' to be definable, and the definition which says that it is 'change of place' deserves respect. | |
From: Gottfried Leibniz (New Essays on Human Understanding [1704], 3.04) | |
A reaction: This seems to be the 'at-at' view of motion, championed by Bertrand Russell. (At p1 at t1, at p2 at t2...). Leibniz's version only mentions space and not time, and it includes 'change', which would need definition without mentioning motion. |
12952 | Space is an order among actual and possible things [Leibniz] |
Full Idea: Space is a relationship: an order, not only among existents, but also among possibles as though they existed. | |
From: Gottfried Leibniz (New Essays on Human Understanding [1704], 2.13) | |
A reaction: The modal end to this idea is a bit puzzling. Would there be any space if there were only possibles, and nothing yet existed, as in God's mind the instant before he got to work? |
12955 | If there were duration without change, we could never establish its length [Leibniz] |
Full Idea: If there were a vacuum in space, one could establish its size. But if there were a vacuum in time, i.e. a duration without change, it would be impossible to establish its length. | |
From: Gottfried Leibniz (New Essays on Human Understanding [1704], 2.15) | |
A reaction: See Idea 4226 for Shoemaker's wonderful counterproposal to this apparently unanswerable claim. I suppose Leibniz is right, but it just might be possible to bring induction to bear on the problem. |
6938 | Natural selection might well fill an animal's mind with pleasing thoughts rather than true ones [Peirce] |
Full Idea: It is probably of more advantage to an animal to have his mind filled with pleasing and encouraging visions, independently of their truth; and thus, upon unpractical subjects, natural selection might occasion a fallacious tendency of thought. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p. 8) | |
A reaction: Note that this is a pragmatist saying that a set of beliefs might work fine but be untrue. So Peirce does not have the highly relativistic notion of truth of some later pragmatists. Good for him. Note the early date to be thinking about Darwin. |