10 ideas
| 5021 | An idea is analysed perfectly when it is shown a priori that it is possible [Leibniz] |
| Full Idea: Every idea is analysed perfectly only when it is demonstrated a priori that it is possible. | |
| From: Gottfried Leibniz (Of Organum or Ars Magna of Thinking [1679], p.3) | |
| A reaction: I take it he means metaphysical possibility, rather than natural, or we can't think about pigs flying. He probably has maths in mind. Seeing the possibility of something may well amount to understanding its truth conditions. |
| 10196 | The Axiom of Choice needs a criterion of choice [Black] |
| Full Idea: Some mathematicians seem to think that talk of an Axiom of Choice allows them to choose a single member of a collection when there is no criterion of choice. | |
| From: Max Black (The Identity of Indiscernibles [1952], p.68) |
| 10194 | Two things can only be distinguished by a distinct property or a distinct relation [Black] |
| Full Idea: The only way we can discover that two things exist is by finding out that one has a quality not possessed by the other, or else that one has a relational characteristic that the other hasn't. | |
| From: Max Black (The Identity of Indiscernibles [1952], p.67) | |
| A reaction: At least this doesn't conflate relations with properties. Note that this idea is clearly epistemological, and in no way rules out the separateness of two objects which none of us can ever discern. Maybe the Earth has two Suns, which imperceptibly swap. |
| 10193 | The 'property' of self-identity is uselessly tautological [Black] |
| Full Idea: Saying that 'a has the property of being identical with a' is a roundabout way of saying nothing - a useless tautology - and means not more than 'a is a' | |
| From: Max Black (The Identity of Indiscernibles [1952], p.66) | |
| A reaction: This matter resembles the problem of the number zero, and the empty set, which seem to be crucial entities for logicians, but of no interest to a common sense view of the world. So much the worse for logic, I am inclined to say. |
| 10195 | If the universe just held two indiscernibles spheres, that refutes the Identity of Indiscernibles [Black] |
| Full Idea: Isn't it logically possible that the universe should have contained nothing but two exactly similar spheres? ...So two things would have all their properties in common, and this would refute the Principle of the Identity of Indiscernibles. | |
| From: Max Black (The Identity of Indiscernibles [1952], p.67) | |
| A reaction: [Black is the originator of this famous example] It also appears to be naturally possible. An observer at an instant of viewing will discern a relational difference relative to themselves. Most people take Black's objection to be decisive. |
| 5020 | Our thoughts are either dependent, or self-evident. All thoughts seem to end in the self-evident [Leibniz] |
| Full Idea: Whatever is thought by us is either conceived through itself, or involves the concept of another. …Thus one must proceed to infinity, or all thoughts are resolved into those which are conceived through themselves. | |
| From: Gottfried Leibniz (Of Organum or Ars Magna of Thinking [1679], p.1) | |
| A reaction: This seems to embody the rationalist attitude to foundations. I am sympathetic. Experiences just come to us as basic, but they don't qualify as 'thoughts', let alone knowledge. Experiences are more 'given' than 'conceptual'. |
| 7518 | If folk psychology gives a network of causal laws, that fits neatly with functionalism [Churchland,PM] |
| Full Idea: The portrait of folk psychology as a network of causal laws dovetailed neatly with the emerging philosophy of mind called functionalism. | |
| From: Paul M. Churchland (Folk Psychology [1996], II) | |
| A reaction: And from the lower levels functionalism is supported by the notion that the brain is modular. Note the word 'laws'; this implies an underlying precision in folk psychology, which is then easily attacked. Maybe the network is too complex for simple laws. |
| 7519 | Many mental phenomena are totally unexplained by folk psychology [Churchland,PM] |
| Full Idea: Folk psychology fails utterly to explain a considerable variety of central psychological phenomena: mental illness, sleep, creativity, memory, intelligence differences, and many forms of learning, to cite just a few. | |
| From: Paul M. Churchland (Folk Psychology [1996], III) | |
| A reaction: If folk psychology is a theory, it will have been developed to predict behaviour, rather than as a full-blown psychological map. The odd thing is that some people seem to be very bad at folk psychology. |
| 7520 | Folk psychology never makes any progress, and is marginalised by modern science [Churchland,PM] |
| Full Idea: Folk psychology has not progressed significantly in the last 2500 years; if anything, it has been steadily in retreat during this period; it does not integrate with modern science, and its emerging wallflower status bodes ill for its future. | |
| From: Paul M. Churchland (Folk Psychology [1996], III) | |
| A reaction: [compressed] However, while shares in alchemy and astrology have totally collapsed, folk psychology shows not the slightest sign of going away, and it is unclear how it ever could. See Idea 3177. |
| 5019 | Supreme human happiness is the greatest possible increase of his perfection [Leibniz] |
| Full Idea: The supreme happiness of man consists in the greatest possible increase of his perfection. | |
| From: Gottfried Leibniz (Of Organum or Ars Magna of Thinking [1679], p.1) | |
| A reaction: I fear that (being a great intellectual) he had a rather intellectual interpretation of 'perfection'. This is in danger of being a tautology, but if the proposal is given an Aritotelian slant I am sympathetic. |