12 ideas
| 13163 | Circles must be bounded, so cannot be infinite [Leibniz] |
| Full Idea: An infinite circle is impossible, since any circle is bounded by its circumference. | |
| From: Gottfried Leibniz (Dialogue on human freedom and origin of evil [1695], p.114) | |
| A reaction: This is interesting if one is asking what the essence of a circle must be. If is tempting to say merely that the radii must be equal, but can they have the length of some vast transfinite number? The circumference must be 2π bigger. |
| 19347 | Substance needs independence, unity, and stability (for individuation); also it is a subject, for predicates [Perkins] |
| Full Idea: For individuation, substance needs three properties: independence, to separate it from other things; unity, to call it one thing, rather than an aggregate; and permanence or stability over time. Its other role is as subject for predicates. | |
| From: Franklin Perkins (Leibniz: Guide for the Perplexed [2007], 3.1) | |
| A reaction: Perkins is describing the Aristotelian view, which is taken up by Leibniz. 'Substance' is not a controversial idea, if we see that it only means that the world is full of 'things'. It is an unusual philosopher wholly totally denies that. |
| 9169 | A statement can be metaphysically necessary and epistemologically contingent [Putnam] |
| Full Idea: A statement can be (metaphysically) necessary and epistemologically contingent. Human intuition has no privileged access to metaphysical necessity. | |
| From: Hilary Putnam (Meaning and Reference [1973], p.160) | |
| A reaction: The terminology here is dangerously confusing. 'Contingent' is a term which (as Kripke insists) refers to reality, not to our epistemological abilities. The locution of adding the phrase "for all I know" seems to handle the problem better. |
| 5819 | Conceivability is no proof of possibility [Putnam] |
| Full Idea: Conceivability is no proof of possibility. | |
| From: Hilary Putnam (Meaning and Reference [1973], p.159) | |
| A reaction: This strikes me as a really basic truth which all novice philosophers should digest. It led many philosophers, especially rationalists, into all sorts of ill-founded claims about what is possible or necessary. Zombies, for instance… |
| 13162 | Sloth's Syllogism: either it can't happen, or it is inevitable without my effort [Leibniz] |
| Full Idea: The ancient Sloth's Syllogism says that if something is foreseen and infallible, it will happen without my effort, and if it is not foreseen, it will not happen, even though I am able to do it. | |
| From: Gottfried Leibniz (Dialogue on human freedom and origin of evil [1695], p.113) | |
| A reaction: Presumable the foreseeing is to be done by the oracle, and not by the slothful person. |
| 9168 | I can't distinguish elm trees, but I mean by 'elm' the same set of trees as everybody else [Putnam] |
| Full Idea: My concept of an elm tree is exactly the same as my concept of a beech tree (I blush to confess). ..We still say that the extension of 'elm' in my idiolect is the same as the extension of 'elm' in anyone else's, viz. the set of all elm trees. | |
| From: Hilary Putnam (Meaning and Reference [1973], p.154) | |
| A reaction: This example is clearer and less open to hair-splitting than his water/XYZ example. You could, with Putnam, say that his meaning of 'elm' is outside his head, but you could also say that he doesn't understand the word very well. |
| 5820 | 'Water' has an unnoticed indexical component, referring to stuff around here [Putnam] |
| Full Idea: Our theory can be summarized as saying that words like 'water' have an unnoticed indexical component: "water" is stuff that bears a certain similarity relation to the water around here. | |
| From: Hilary Putnam (Meaning and Reference [1973], p.160) | |
| A reaction: This is the causal theory of reference, which leads to externalism about concepts, which leads to an externalist view of thought, which undermines internal accounts of the mind like functionalism, and leaves little room for scepticism… Etc. |
| 9170 | We need to recognise the contribution of society and of the world in determining reference [Putnam] |
| Full Idea: Traditional semantic theory leaves out two contributions to the determination of reference - the contribution of society and the contribution of the real world; a better semantic theory must encompass both. | |
| From: Hilary Putnam (Meaning and Reference [1973], p.161) | |
| A reaction: I strongly agree that there is a social aspect to reference-fixing, but I am much more dubious about the world 'determining' anything. The whole of his Twin Earth point could be mopped up by a social account, with 'experts' as the key idea. |
| 5817 | Language is more like a cooperative steamship than an individual hammer [Putnam] |
| Full Idea: There are tools like a hammer used by one person, and there are tools like a steamship which require cooperative activity; words have been thought of too much on the model of the first sort of tool. | |
| From: Hilary Putnam (Meaning and Reference [1973], p.156) | |
| A reaction: This clear thought strikes me as the most fruitful and sensible consequence of Wittgenstein's later ideas (as opposed to the relativistic 'language game' ideas). I am unconvinced that a private language is logically impossible, but it would be feeble. |
| 5818 | If water is H2O in the actual world, there is no possible world where it isn't H2O [Putnam] |
| Full Idea: Once we have discovered that water (in the actual world) is H2O, nothing counts as a possible world in which water isn't H2O. | |
| From: Hilary Putnam (Meaning and Reference [1973], p.159) | |
| A reaction: Presumably there could be a possible world in which water is a bit cloudy, so the fact that it is H2O is being judged as essential. Presumably the scientists in the possible world might discover that we are wrong about the chemistry of water? |
| 19339 | Evil is a negation of good, which arises from non-being [Leibniz] |
| Full Idea: The cause of good is positive, but evil is a defect, that is, a privation or negation, and consequently, it arises from nothingness or nonbeing. | |
| From: Gottfried Leibniz (Dialogue on human freedom and origin of evil [1695], p.114) | |
| A reaction: He goes on to illustrate his idea from mathematics. He is modifying Augustine's view that evil is an absence of good, by adding nonbeing as the driving force behind it. Doesn't sound very persuasive to me. |
| 13164 | God only made sin possible because a much greater good can be derived from it [Leibniz] |
| Full Idea: We must believe that God would not have allowed sin nor would he have created things he knows will sin, if he could not derive from them a good incomparably greater than the resulting evil. | |
| From: Gottfried Leibniz (Dialogue on human freedom and origin of evil [1695], p.115) | |
| A reaction: Why 'must' we believe this? Do we have to imagine all the genocides shrinking to insignificance once we grasp the wonderful goods that can be derived from them? The end justifies the means. Genocide is actually a good thing. Hm. |