18 ideas
8766 | In much wisdom is much grief [Anon (Ecc)] |
Full Idea: In much wisdom is much grief. | |
From: Anon (Ecc) (21: Book of Ecclesiastes [c.200 BCE], 01.18) | |
A reaction: If this is true, then the question is of what there is in wisdom that will compensate for the grief. Personally I doubt the whole claim. Some wisdom involves grief, but most of it involves pleasure, even when understanding of evil is the target. |
7494 | Laughter is mad; of mirth, what doeth it? [Anon (Ecc)] |
Full Idea: I said of laughter, It is mad: and of mirth, what doeth it? | |
From: Anon (Ecc) (21: Book of Ecclesiastes [c.200 BCE], 02.02) | |
A reaction: Not much of an argument, but an interesting support for the extreme anti-hedonistic puritanical view. Most people would praise laughter as an end in itself, so 'what doeth it?' seems to miss the point. |
8767 | Sorrow is better than laughter [Anon (Ecc)] |
Full Idea: Sorrow is better than laughter: for by the sadness of the countenance the heart is made better. | |
From: Anon (Ecc) (21: Book of Ecclesiastes [c.200 BCE], 07.03) | |
A reaction: This writer fails to see the good in laughter. If he did, he would have a more balanced view, and we could take this opinion more seriously. Theatre audiences always seem keen to hunt out jokes where none are intended. |
14240 | The empty set is something, not nothing! [Oliver/Smiley] |
Full Idea: Some authors need to be told loud and clear: if there is an empty set, it is something, not nothing. | |
From: Oliver,A/Smiley,T (What are Sets and What are they For? [2006], 1.2) | |
A reaction: I'm inclined to think of a null set as a pair of brackets, so maybe that puts it into a metalanguage. |
14241 | We don't need the empty set to express non-existence, as there are other ways to do that [Oliver/Smiley] |
Full Idea: The empty set is said to be useful to express non-existence, but saying 'there are no Us', or ¬∃xUx are no less concise, and certainly less roundabout. | |
From: Oliver,A/Smiley,T (What are Sets and What are they For? [2006], 1.2) |
14239 | The empty set is usually derived from Separation, but it also seems to need Infinity [Oliver/Smiley] |
Full Idea: The empty set is usually derived via Zermelo's axiom of separation. But the axiom of separation is conditional: it requires the existence of a set in order to generate others as subsets of it. The original set has to come from the axiom of infinity. | |
From: Oliver,A/Smiley,T (What are Sets and What are they For? [2006], 1.2) | |
A reaction: They charge that this leads to circularity, as Infinity depends on the empty set. |
14242 | Maybe we can treat the empty set symbol as just meaning an empty term [Oliver/Smiley] |
Full Idea: Suppose we introduce Ω not as a term standing for a supposed empty set, but as a paradigm of an empty term, not standing for anything. | |
From: Oliver,A/Smiley,T (What are Sets and What are they For? [2006], 1.2) | |
A reaction: This proposal, which they go on to explore, seems to mean that Ω (i.e. the traditional empty set symbol) is no longer part of set theory but is part of semantics. |
14243 | The unit set may be needed to express intersections that leave a single member [Oliver/Smiley] |
Full Idea: Thomason says with no unit sets we couldn't call {1,2}∩{2,3} a set - but so what? Why shouldn't the intersection be the number 2? However, we then have to distinguish three different cases of intersection (common subset or member, or disjoint). | |
From: Oliver,A/Smiley,T (What are Sets and What are they For? [2006], 2.2) |
14234 | If you only refer to objects one at a time, you need sets in order to refer to a plurality [Oliver/Smiley] |
Full Idea: A 'singularist', who refers to objects one at a time, must resort to the language of sets in order to replace plural reference to members ('Henry VIII's wives') by singular reference to a set ('the set of Henry VIII's wives'). | |
From: Oliver,A/Smiley,T (What are Sets and What are they For? [2006], Intro) | |
A reaction: A simple and illuminating point about the motivation for plural reference. Null sets and singletons give me the creeps, so I would personally prefer to avoid set theory when dealing with ontology. |
14237 | We can use plural language to refer to the set theory domain, to avoid calling it a 'set' [Oliver/Smiley] |
Full Idea: Plurals earn their keep in set theory, to answer Skolem's remark that 'in order to treat of 'sets', we must begin with 'domains' that are constituted in a certain way'. We can speak in the plural of 'the objects', not a 'domain' of objects. | |
From: Oliver,A/Smiley,T (What are Sets and What are they For? [2006], Intro) | |
A reaction: [Skolem 1922:291 in van Heijenoort] Zermelo has said that the domain cannot be a set, because every set belongs to it. |
14245 | Logical truths are true no matter what exists - but predicate calculus insists that something exists [Oliver/Smiley] |
Full Idea: Logical truths should be true no matter what exists, so true even if nothing exists. The classical predicate calculus, however, makes it logically true that something exists. | |
From: Oliver,A/Smiley,T (What are Sets and What are they For? [2006], 5.1) |
14246 | If mathematics purely concerned mathematical objects, there would be no applied mathematics [Oliver/Smiley] |
Full Idea: If mathematics was purely concerned with mathematical objects, there would be no room for applied mathematics. | |
From: Oliver,A/Smiley,T (What are Sets and What are they For? [2006], 5.1) | |
A reaction: Love it! Of course, they are using 'objects' in the rather Fregean sense of genuine abstract entities. I don't see why fictionalism shouldn't allow maths to be wholly 'pure', although we have invented fictions which actually have application. |
14247 | Sets might either represent the numbers, or be the numbers, or replace the numbers [Oliver/Smiley] |
Full Idea: Identifying numbers with sets may mean one of three quite different things: 1) the sets represent the numbers, or ii) they are the numbers, or iii) they replace the numbers. | |
From: Oliver,A/Smiley,T (What are Sets and What are they For? [2006], 5.2) | |
A reaction: Option one sounds the most plausible to me. I will take numbers to be patterns embedded in nature, and sets are one way of presenting them in shorthand form, in order to bring out what is repeated. |
19400 | Possibles demand existence, so as many of them as possible must actually exist [Leibniz] |
Full Idea: From the conflict of all the possibles demanding existence, this at once follows, that there exists that series of things by which as many of them as possible exist. | |
From: Gottfried Leibniz (Exigency to Exist in Essences [1690], p.91) | |
A reaction: I'm in tune with a lot of Leibniz, but my head swims with this one. He seems to be a Lewisian about possible worlds - that they are concrete existing entities (with appetites!). Could Lewis include Leibniz's idea in his system? |
19401 | God's sufficient reason for choosing reality is in the fitness or perfection of possibilities [Leibniz] |
Full Idea: The sufficient reason for God's choice can be found only in the fitness (convenance) or in the degree of perfection that the several worlds possess. | |
From: Gottfried Leibniz (Exigency to Exist in Essences [1690], p.92) | |
A reaction: The 'fitness' of a world and its 'perfection' seem very different things. A piece of a jigsaw can have wonderful fitness, without perfection. Occasionally you get that sinking feeling with metaphysicians that they just make it up. |
19402 | The actual universe is the richest composite of what is possible [Leibniz] |
Full Idea: The actual universe is the collection of the possibles which forms the richest composite. | |
From: Gottfried Leibniz (Exigency to Exist in Essences [1690], p.92) | |
A reaction: 'Richest' for Leibniz means a maximum combination of existence, order and variety. It's rather like picking the best starting team from a squad of footballers. |
8765 | All is vanity, saith the Preacher [Anon (Ecc)] |
Full Idea: Vanity of vanities, saith the Preacher, vanity of vanities; all is vanity. | |
From: Anon (Ecc) (21: Book of Ecclesiastes [c.200 BCE], 01.02) | |
A reaction: If we are swamped by vanity, then there is presumably no hope for the other virtues. A more balanced view would say that we should aim for a mean on the scale of self-esteem, which probably requires an effort to be objective about ourselves. |
8768 | Books are endless, and study is wearisome [Anon (Ecc)] |
Full Idea: Of making many books there is no end; and much study is weariness of the flesh. | |
From: Anon (Ecc) (21: Book of Ecclesiastes [c.200 BCE], 12.12) | |
A reaction: Does anyone share my occasional sinking heart on entering a large library or bookshop? I truly believe that there is nothing better in the world than books. And yet, and yet... |