16 ideas
| 15842 | An ad hominem refutation is reasonable, if it uses the opponent's assumptions [Harte,V] |
| Full Idea: Judicious use of an opponent's assumptions is quite capable of producing a perfectly reasonable ad hominem refutation of the opponent's thesis. | |
| From: Verity Harte (Plato on Parts and Wholes [2002], 1.6) |
| 15841 | Mereology began as a nominalist revolt against the commitments of set theory [Harte,V] |
| Full Idea: Historically, the evolution of mereology was associated with the desire to find alternatives to set theory for those with nomimalist qualms about the commitment to abstract objects like sets. | |
| From: Verity Harte (Plato on Parts and Wholes [2002], 1.2) | |
| A reaction: Goodman, for example. It is interesting to note that the hardline nominalist Quine, pal of Goodman, eventually accepted set theory. It is difficult to account for things by merely naming their parts. |
| 1507 | We don't have time for infinite quantity, but we do for infinite divisibility, because time is also divisible [Aristotle on Zeno of Elea] |
| Full Idea: Although it is impossible to make contact in a finite time with things that are infinite in quantity, it is possible to do so with things that are infinitely divisible, since the time itself is also infinite in this way. | |
| From: comment on Zeno (Elea) (fragments/reports [c.450 BCE], A25) by Aristotle - Physics 233a21 |
| 5109 | The fast runner must always reach the point from which the slower runner started [Zeno of Elea, by Aristotle] |
| Full Idea: Zeno's so-called 'Achilles' claims that the slowest runner will never be caught by the fastest runner, because the one behind has first to reach the point from which the one in front started, and so the slower one is bound always to be in front. | |
| From: report of Zeno (Elea) (fragments/reports [c.450 BCE]) by Aristotle - Physics 239b14 | |
| A reaction: The point is that the slower runner will always have moved on when the faster runner catches up with the starting point. We must understand how humble the early Greeks felt when they confronted arguments like this. It was like a divine revelation. |
| 1512 | Zeno is wrong that one grain of millet makes a sound; why should one grain achieve what the whole bushel does? [Aristotle on Zeno of Elea] |
| Full Idea: Zeno is wrong in arguing that the tiniest fragment of millet makes a sound; there is no reason why the fragment should be able to move in any amount of time the air which the whole bushel moved as it fell. | |
| From: comment on Zeno (Elea) (fragments/reports [c.450 BCE], A29) by Aristotle - Physics 250a16 |
| 1508 | Zeno's arrow paradox depends on the assumption that time is composed of nows [Aristotle on Zeno of Elea] |
| Full Idea: Zeno's third argument claims that a moving arrow is still. Here the conclusion depends on assuming that time is composed of nows; if this assumption is not granted, the argument fails. | |
| From: comment on Zeno (Elea) (fragments/reports [c.450 BCE], A27?) by Aristotle - Physics 239b5 |
| 15858 | Traditionally, the four elements are just what persists through change [Harte,V] |
| Full Idea: Earth, air, fire and water, viewed as elements, are, by tradition, the leading candidates for being the things that persist through change. | |
| From: Verity Harte (Plato on Parts and Wholes [2002], 4.4) | |
| A reaction: Physics still offers us things that persist through change, as conservation laws. |
| 15848 | Mereology treats constitution as a criterion of identity, as shown in the axiom of extensionality [Harte,V] |
| Full Idea: Mereologists do suppose that constitution is a criterion of identity. This view is enshrined in the Mereological axiom of extensionality; that objects with the same parts are identical. | |
| From: Verity Harte (Plato on Parts and Wholes [2002], 3.1) | |
| A reaction: A helpful explanation of why classical mereology is a very confused view of the world. It is at least obvious that a long wall and a house are different things, even if built of identical bricks. |
| 15837 | What exactly is a 'sum', and what exactly is 'composition'? [Harte,V] |
| Full Idea: The difficulty with the claim that a whole is (just) the sum of its parts is what are we to understand by 'the sum'? ...If we say wholes are 'composites' of parts, how are we to understand the relation of composition? | |
| From: Verity Harte (Plato on Parts and Wholes [2002], 1.1) |
| 15839 | If something is 'more than' the sum of its parts, is the extra thing another part, or not? [Harte,V] |
| Full Idea: Holism inherits all the difficulties associated with the term 'sum' and adds one of its own, when it says a whole is 'more than' the sum of its parts. This seems to say it has something extra? Is this something extra a part? | |
| From: Verity Harte (Plato on Parts and Wholes [2002], 1.1) | |
| A reaction: [compressed] Most people take the claim that a thing is more than the sum of its parts as metaphorical, I would think (except perhaps emergentists about the mind, and they are wrong). |
| 15838 | The problem with the term 'sum' is that it is singular [Harte,V] |
| Full Idea: For my money, the real problem with the term 'sum' is that it is singular. | |
| From: Verity Harte (Plato on Parts and Wholes [2002], 1.1) | |
| A reaction: Her point is that the surface grammar makes you accept a unity here, with no account of what unifies it, or even whether there is a unity. Does classical mereology have a concept (as the rest of us do) of 'disunity'? |
| 13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
| Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
| From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
| A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
| 454 | If there are many things they must have a finite number, but there must be endless things between them [Zeno of Elea] |
| Full Idea: It things are many, they can't be more or less than they are, so they must be finite, but also there must be endless things between each thing, so they must be infinite. | |
| From: Zeno (Elea) (fragments/reports [c.450 BCE], B3), quoted by Simplicius - On Aristotle's 'Physics' 140.29 |
| 455 | That which moves, moves neither in the place in which it is, nor in that in which it is not [Zeno of Elea] |
| Full Idea: That which moves, moves neither in the place in which it is, nor in that in which it is not. | |
| From: Zeno (Elea) (fragments/reports [c.450 BCE], B4), quoted by (who?) - where? |
| 1511 | If everything is in a place, what is the place in? Place doesn't exist [Zeno of Elea, by Simplicius] |
| Full Idea: If there is a place it will be in something, because everything that exists is in something. But what is in something is in a place. Therefore the place will be in a place, and so on ad infinitum. Therefore, there is no such thing as place. | |
| From: report of Zeno (Elea) (fragments/reports [c.450 BCE], B3) by Simplicius - On Aristotle's 'Physics' 9.562.3 |
| 20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
| Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
| From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
| A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |