45 ideas
| 18450 | Philosophy has its own mode of death, by separating soul from body [Porphyry] |
| Full Idea: There is a double death. One, known by all men, consists in the separation of the body with the soul; the other, characteristic of philosophers, results in the separation of the soul from the body. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 1Enn9 3) |
| 18451 | The presence of the incorporeal is only known by certain kinds of disposition [Porphyry] |
| Full Idea: Being everywhere and nowhere, the incorporeal, wherever it happens to be, betrays its presence only by a certain kind of disposition. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 4Enn3 21(20)) | |
| A reaction: There is a mystical or dualist view of fundamental powers, as the spiritual engine which drives passive physical nature. It's rubbish of course, but if powers are primitive in a naturalistic theory, it is not a view which can be refuted. |
| 15034 | Are genera and species real or conceptual? bodies or incorporeal? in sensibles or separate from them? [Porphyry] |
| Full Idea: I shall beg off talking of a) whether genera and species are real or situated in bare thoughts alone, b) whether as real they are bodies or incorporeals, and c) whether they are separated or in sensibles and have their reality in connection with them. | |
| From: Porphyry (Isagoge ('Introduction') [c.295], (2)) | |
| A reaction: This passage, picking up on Aristotle, seems to be the original source that grew into the medievel debate about universals. It seems to rather neatly lay out the agenda for the universals debate which is still with us. |
| 18459 | Diversity arises from the power of unity [Porphyry] |
| Full Idea: Diversity is born of the development of the power of unity. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 6Enn5 42) | |
| A reaction: I doubt whether even Porphyry understood this, but we might say that once the principle of unification enters into nature, it will inevitably result in diversity. One all-embracing unity would be indiscernible. |
| 6346 | The main epistemological theories are foundationalist, coherence, probabilistic and reliabilist [Pollock/Cruz] |
| Full Idea: The most familiar epistemological theories are foundation theories, coherence theories, probabilistic theories, and reliabilist theories. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], Pref) | |
| A reaction: A helpful list. Reliabilism is now the dominant externalist theory. Probability theories will centre on Bayes' Theorem (Idea 2798). The authors want an internalist theory that includes perceptions as well as beliefs. I currently favour coherence. |
| 6351 | Most people now agree that our reasoning proceeds defeasibly, rather than deductively [Pollock/Cruz] |
| Full Idea: One of the most important modern advances in epistemology was the recognition of defeasible reasons; it is now generally acknowledged that most of our reasoning proceeds defeasibly rather than deductively. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §1.2) | |
| A reaction: I agree totally. This is why fallibilism is clearly a correct position in epistemology (e.g. Ideas 2736 and 2755). Deduction is not the only grounds given for certainty - there are rationalist foundations (Descartes) and empiricist foundations (Moore). |
| 6374 | To believe maximum truths, believe everything; to have infallible beliefs, believe nothing [Pollock/Cruz] |
| Full Idea: If we want an agent to believe as many truths as possible, this could be achieved by simply believing everything; if we want an agent to have only true beliefs, this could be achieved by believing nothing. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §6.6) | |
| A reaction: I like this. It highlights the pragmatic need for a middle road, in which a core set of beliefs are going to be approved of as 'knowledge', so that we can get on with life. This has to be a social matter, and needs flexibility of Fallibilism. |
| 6355 | Direct realism says justification is partly a function of pure perceptual states, not of beliefs [Pollock/Cruz] |
| Full Idea: We defend a version of direct realism, saying that justification must be partly a function of perceptual states themselves, and not just a function of our beliefs about perceptual states. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §1.5.3) | |
| A reaction: Judgement suggests that perceptual states give good justification about primary qualities (like mass or shape), but not of secondary qualities (like smell or colour). Perceptions can be downright misleading. |
| 6359 | Phenomenalism offered conclusive perceptual knowledge, but conclusive reasons no longer seem essential [Pollock/Cruz] |
| Full Idea: Phenomenalism offered the prospect of explaining perceptual knowledge within a framework that recognised only conclusive reasons; once it is acknowledged that at least induction uses nonconclusive reasons, it is no longer needed. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.3.3.2) | |
| A reaction: I'm not sure that that is the only motivation for phenomenalism, which seemed to be attempting to get as close to 'reality' as intellectual honesty would allow. I certainly favour the modern relaxed attitude to knowledge, which needn't be 'conclusive'. |
| 6366 | Perception causes beliefs in us, without inference or justification [Pollock/Cruz] |
| Full Idea: Perception is a causal process that inputs beliefs into our doxastic system without their being inferred from or justified on the basis of other beliefs we already have. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §3.2.3) | |
| A reaction: This topic is much discussed (e.g. by MacDowell). I don't see how something is going to qualify as a 'belief' if it doesn't involve concepts and propositions. The point that we are caused to have many of our beliefs (rather than judging) seems right. |
| 6362 | Sense evidence is not beliefs, because they are about objective properties, not about appearances [Pollock/Cruz] |
| Full Idea: We think it is a mistake to suppose that the evidence of our senses comes to us in the form of beliefs; in perception, the beliefs we form are almost invariably about the objective properties of physical objects - not about how they appear to us. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.5.5) | |
| A reaction: The tricky word here is 'evidence'. At what point in the process of perception does something begin to count as evidence? It must at least involve concepts (and maybe even propositions) if it is going to be thought about in that way. |
| 18452 | Memory is not conserved images, but reproduction of previous thought [Porphyry] |
| Full Idea: Memory does not consist in preserving images. It is a faculty of reproducing the conceptions with which our soul has been occupied. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 5Enn6 25(2)) |
| 6371 | Bayesian epistemology is Bayes' Theorem plus the 'simple rule' (believe P if it is probable) [Pollock/Cruz] |
| Full Idea: Bayesian epistemology is based upon the 'simple rule' (believe P if it is sufficiently probable) and Bayes' Theorem. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §4.3.1) | |
| A reaction: For Bayes' Theorem, see Idea 2798. There is the question of whether the proposition is subjectively or objectively probable (I believe in ghosts, so any shadow is probably a ghost). There is also the problem of objective evidence for the calculation. |
| 6373 | Internalism says if anything external varies, the justifiability of the belief does not vary [Pollock/Cruz] |
| Full Idea: Internalist theories make justifiability of a belief a function of the internal states of the believer, in the sense that if we vary anything but his internal states the justifiability of the belief does not vary. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §5.4.3) | |
| A reaction: This seems to be a nice clear definition of internalism (and, by implication, externalism). It favours externalism. I know my car is in the car park; someone takes it for a joyride, then replaces it; my good justification seems thereby weakened. |
| 6353 | People rarely have any basic beliefs, and never enough for good foundations [Pollock/Cruz] |
| Full Idea: We argue that all foundations theories are false, for the simple reason that people rarely have any epistemological basic beliefs, and never have enough to provide a foundation for the rest of our knowledge. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §1.5.3) | |
| A reaction: Once surprising things start to happen in a film, we rapidly jettison our normal basic beliefs, to be ready for surprises. However, it seems to me that quite a lot of beliefs are hard-wired into us, or inescapably arise from the use of our senses. |
| 6361 | Foundationalism requires self-justification, not incorrigibility [Pollock/Cruz] |
| Full Idea: What foundationalism requires is self-justification, which is weaker than incorrigibility. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.5.3) | |
| A reaction: The writers oppose foundationalism, but this remark obviously helps the theory. Bonjour votes for a fallible rationalist foundationalism, and an fallible empiricist version seems plausible (because we must check for hallucinations etc.). |
| 6357 | Reason cannot be an ultimate foundation, because rational justification requires prior beliefs [Pollock/Cruz] |
| Full Idea: Reasoning, it seems, can only justify us in holding a belief if we are already justified in holding the beliefs from which we reason, so reasoning cannot provide an ultimate source of justification. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.1) | |
| A reaction: This sounds slick and conclusive, but it isn't. If we accept that some truths might be 'self-evident' to reason, they could stand independently. And a large body of rational beliefs might be mutually self-supporting, as in the coherence theory of truth. |
| 6363 | Foundationalism is wrong, because either all beliefs are prima facie justified, or none are [Pollock/Cruz] |
| Full Idea: Either no belief is prima facie justified or all beliefs are prima facie justified; …we regard this as a decisive refutation of foundationalism. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.5.5) | |
| A reaction: The full text must he examined, but it is not at all clear to me how my belief that quantum theory is correct could be even remotely as prima facie justified as my belief that this is my hand. I don't think basic beliefs need be sharply divided off. |
| 6365 | Negative coherence theories do not require reasons, so have no regress problem [Pollock/Cruz] |
| Full Idea: The regress argument has no apparent strength against negative coherence theories, because they do not require reasons for beliefs. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §3.2.3) | |
| A reaction: A nice point. Such theories endorse Neurath's picture (Idea 6348). On the whole philosophers like positive support for their beliefs, so the rather passive picture of accepting everything unless it is undermined is not appealing. A fall-back position. |
| 6354 | Coherence theories fail, because they can't accommodate perception as the basis of knowledge [Pollock/Cruz] |
| Full Idea: All coherence theories fail, because they are unable to accommodate perception as the basic source of our knowledge of the world. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §1.5.3) | |
| A reaction: An interesting claim, which the authors attempt to justify. They say it is direct realism, because the perceptions justify, without any intervening beliefs. My immediate thought is that they might justify knowledge of primary qualities, but not secondary. |
| 6367 | Coherence theories isolate justification from the world [Pollock/Cruz] |
| Full Idea: The Isolation Argument objects that coherence theories cut justification off from the world. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §3.2.4) | |
| A reaction: I don't see this as a strong objection. Justification can be in the way beliefs cohere together, but the beliefs themselves consist of holding propositions to be true, and truth asserts a connection to the world (I say). |
| 6370 | Externalism comes as 'probabilism' (probability of truth) and 'reliabilism' (probability of good cognitive process) [Pollock/Cruz] |
| Full Idea: There are two major kinds of externalist theory in the literature - probabilism (which expresses justification in terms of probability of the belief being true), and reliabilism (which refers to the probability of the cognitive processes being right). | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §4.1) | |
| A reaction: A useful clarification. Reliabilism has an obvious problem, that a process can be reliable, but only luckily correct on this occasion (a clock which has, unusually, stopped). A ghost is more probably there if I believe in ghosts. |
| 6358 | One belief may cause another, without being the basis for the second belief [Pollock/Cruz] |
| Full Idea: If I fall flat on my back running to a class, my belief that I was late for class may cause me to have the belief that there are birds in the trees, but I do not believe the latter on the basis of the former. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.3.1) | |
| A reaction: A nice example, which fairly conclusively demolishes any causal theory of justification. My example is believing correctly that the phone ring is from mother, because she said she would call. Maybe causation is needed somewhere in the right theory. |
| 6364 | We can't start our beliefs from scratch, because we wouldn't know where to start [Pollock/Cruz] |
| Full Idea: We cannot forsake all of our beliefs and start over again, because then we could not know how to start. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §3.1) | |
| A reaction: A point with which it is hard to disagree, but even Descartes agreed with it (Idea 3604). Presumably all your beliefs can take it in turn to be doubted, while others are held true, or you can whittle the beliefs which can't be abandoned down to a minimum. |
| 6352 | Enumerative induction gives a universal judgement, while statistical induction gives a proportion [Pollock/Cruz] |
| Full Idea: Enumerative induction examines a sample of objects, observes they all have a property, and infers that they all have that property; statistical induction observes a proportion of the objects having the property, and infers that proportion in general. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §1.4.6) | |
| A reaction: There is also induction by elimination, where it is either p or q, and observation keeps saying it isn't p. A small sample is very unreliable, but a huge sample (e.g. cigarettes and cancer) is almost certain, so where is the small/huge boundary? |
| 6372 | Since every tautology has a probability of 1, should we believe all tautologies? [Pollock/Cruz] |
| Full Idea: It follows from the probability calculus that every tautology has probability 1; it then follows in Bayesian epistemology that we are justified in believing every tautology. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §4.3.1.5) | |
| A reaction: If I say 'a bachelor is a small ant' you wouldn't believe it, but if I said 'I define a bachelor as a small ant' you would have to believe it. 'Bachelors are unmarried' men is a description of English usage, so is not really a simple tautology. |
| 20653 | Six reduction levels: groups, lives, cells, molecules, atoms, particles [Putnam/Oppenheim, by Watson] |
| Full Idea: There are six 'reductive levels' in science: social groups, (multicellular) living things, cells, molecules, atoms, and elementary particles. | |
| From: report of H.Putnam/P.Oppenheim (Unity of Science as a Working Hypothesis [1958]) by Peter Watson - Convergence 10 'Intro' | |
| A reaction: I have the impression that fields are seen as more fundamental that elementary particles. What is the status of the 'laws' that are supposed to govern these things? What is the status of space and time within this picture? |
| 6360 | Scientific confirmation is best viewed as inference to the best explanation [Pollock/Cruz] |
| Full Idea: The confirmation of scientific theories is probably best viewed in terms of inference to the best explanation. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.3.3.3) | |
| A reaction: A simple claim, but one with which I strongly agree. 'Inference', of course, implies that there is some fairly strict logical thinking going on, which may not be so. I suspect that dogs can move to the best explanation. It is, though, a rational process. |
| 18453 | Intelligence is aware of itself, so the intelligence is both the thinker and the thought [Porphyry] |
| Full Idea: Since intelligence is intelligible for intelligence, intelligence is its own object. ...Intelligence, therefore, is simultaneously thinker and thought, all that thinks and all that is thought. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 5Enn3 32(5-7)) | |
| A reaction: This is a bit of a problem for Descartes, if the Cogito is taken as offering evidence (thought) for the existence of a thinker ('I'). Porphyry implies that the separation Descartes requires is impossible. |
| 18462 | The soul is everywhere and nowhere in the body, and must be its cause [Porphyry] |
| Full Idea: The soul is neither a body, nor in the body, but is only the cause of the body, because she is simultaneously everywhere and nowhere in the body. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 6Enn5 43) | |
| A reaction: This is the rather bewildering phenomenology of consciousness which persuaded Descartes of dualism. |
| 18463 | Successful introspection reveals the substrate along with the object of thought [Porphyry] |
| Full Idea: He who by thought can penetrate within his own substance, and can thus acquire knowledge of it, finds himself in this actualisation of knowledge and consciousness, where the substrate that knows is identical with the object that is known. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 6Enn5 44) | |
| A reaction: It seems remarkably that this ability is confidently asserted by Porphyry, and flatly denied by Hume. Were they just different people, or were they looking for different things, or was one of them deluded? |
| 18458 | The soul is bound to matter by the force of its own disposition [Porphyry] |
| Full Idea: The individual soul, which declines towards matter, is bound to the matter by the form which her disposition has made her choose. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 6Enn4 39) | |
| A reaction: This sounds like the soul is boss over the matter, and yet the soul is 'made' to choose union with matter. The Universal Soul is seen by Porphyr as the controller of the situation. |
| 18464 | Justice is each person fulfilling his function [Porphyry] |
| Full Idea: Justice, as has been rightly said, consists in each one fulfilling his [authentic and proper] function. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 6Enn5 44) | |
| A reaction: This is presumably a direct reference to the theory in Plato's 'Republic'. It makes the connection between virtue and function which I take to be basic to virtue theory, giving it a naturalistic advantaged over other theories. |
| 18448 | We should avoid the pleasures of love, or at least, should not enact our dreams [Porphyry] |
| Full Idea: The pleasures of love will not even involuntarily be tasted, at least, she will not allow herself to be drawn beyond the lights of fancy that occur in dreams. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 1Enn2 I.4) | |
| A reaction: Presumably erotic dreams are only tolerated because not much can be done about them. This brings out the puritanism of neo-platonism. |
| 18444 | Civil virtues make us behave benevolently, and thereby unite citizens [Porphyry] |
| Full Idea: The object of the civil virtues is to make us benevolent in our dealings with our fellow-human beings, and are so-called because they unite citizens. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 1Enn2 I.1) | |
| A reaction: Modern commentators underestimate the close link between ancient virtue and citizenship. It is hard for one person to have much of a notion of virtue if they live on a desert island, beyond caring for personal health. |
| 18445 | Civil virtues control the passions, and make us conform to our nature [Porphyry] |
| Full Idea: The civil virtues moderate the passions; their object is to teach us to live in conformity with the laws of human nature. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 1Enn2 I.2) | |
| A reaction: The link with human nature is basic to virtue theory, but this proposal is rather too vague. Are passions not part of the laws of human nature? |
| 18446 | Purificatory virtues detach the soul completely from the passions [Porphyry] |
| Full Idea: The object of the 'purificatory' virtues is to detach the soul completely from the passions. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 1Enn2 I.4) | |
| A reaction: This is an aspect of virtue theory which doesn't appear in Aristotle. He is in favour of rational control of the passions, but not of totally abandoning them. The neo-platonists are much more puritanical. They seem to go against human nature. |
| 18447 | There are practical, purificatory, contemplative, and exemplary virtues [Porphyry] |
| Full Idea: The practical virtues make man virtuous; the purificatory virtues make man divine....; the contemplative virtues defiy; while the exemplary virtues make a man the parent of divinities. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 1Enn2 I.4) | |
| A reaction: I like the idea of the 'exemplary' virtues. I think an entire theory of morality could be built on the notion that we are all role-models for one another. |
| 18456 | Unified real existence is neither great nor small, though greatness and smallness participate in it [Porphyry] |
| Full Idea: By its identity and numerical unity, real existence is neither great nor small, neither very large nor very small, though it causes even greatest and smallest to participate in its nature. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 6Enn4 37(5)) | |
| A reaction: Note the platonic word 'participate' [metechein], suggesting that he is talking about the Form of Existence here. Note also that we have 'real' existence here, implying a lesser type of existence that participates in it. |
| 18454 | Time is the circular movement of the soul [Porphyry] |
| Full Idea: It is the circular movement of the soul that constitutes time, just as the permanence of intelligence in itself constitutes eternity. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 5Enn3 32(5-7)) | |
| A reaction: Plato loved circles. If you think time is subjective, this is trying to express your intuition. Personally I think it is nonsense |
| 18455 | Some think time is seen at rest, as well as in movement [Porphyry] |
| Full Idea: Some have believed that time manifested in rest as well as in movement. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 5Enn3 32(5-7)) | |
| A reaction: If you like this idea, you should see Shoemaker's lovely three-worlds thought experiment. |
| 18460 | God is nowhere, and hence everywhere [Porphyry] |
| Full Idea: The divinity is everywhere because it is nowhere. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 6Enn5 43) |
| 18461 | Everything existing proceeds from divinity, and is within divinity [Porphyry] |
| Full Idea: All things that possess or do not possess existence proceed from divinity, and are within divinity. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 6Enn5 43) | |
| A reaction: Nice to see Porphyry endorsing Meinongian objects. I doubt whether he counts as a pantheist, but this is a very pantheistic remark. |
| 18449 | Nature binds or detaches body to soul, but soul itself joins and detaches soul from body [Porphyry] |
| Full Idea: Nature binds the body to the soul, but it is the soul herself that has bound herself to the body. It, therefore, belongs to nature to detach the body from the soul, while it is the soul herself that detaches herself from the body. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 1Enn9 2) | |
| A reaction: Baffling. What happens if there is a conflict? I suppose either party can cancel the bargain, but who wins when they disagree? |
| 18457 | Individual souls are all connected, though distinct, and without dividing universal Soul [Porphyry] |
| Full Idea: Individual souls are distinct without being separated from each other, and without dividing the universal Soul into a number of parts; they are united to each other without becoming confused. | |
| From: Porphyry (Launching Points to the Realm of the Mind [c.280], 6Enn4 39) | |
| A reaction: This sounds like Jung's theory that there is a universal subconscious which links us all together. Taken literally, I assume it is nonsense. As an invitation to acknowledge how much we all have in common, it is a nice corrective to liberal individualism. |