49 ideas
| 3656 | The greatest good for a state is true philosophers [Descartes] |
| Full Idea: The greatest good which can exist in a state is to have true philosophers. | |
| From: René Descartes (Principles of Philosophy [1646], Pref) | |
| A reaction: …because they understand true reality, especially the Good. |
| 14027 | If we are to use words in enquiry, we need their main, unambiguous and uncontested meanings [Epicurus] |
| Full Idea: It is necessary that we look to the primary conception corresponding to each word and that it stand in no need of demonstration, if, that is, we are going to have something to which we can refer the object of search or puzzlement and opinion. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 38) | |
| A reaction: This either points to definition or to consensus, and since definition seems in danger of some sort of Quinean circularity, I favour consensus. Philosophy is, after all, people discussing things, not inscriptions sent to the gods. |
| 14040 | Observation and applied thought are always true [Epicurus] |
| Full Idea: Everything that is observed or grasped by the intellect in an act of application is true. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 62) | |
| A reaction: Not quite clear what he means, but Epicurus is committed to perception as the source of knowledge, with the intellect extending the findings of the senses. He might subscribe to Descartes's 'clear and distinct' perceptions. |
| 14028 | Nothing comes to be from what doesn't exist [Epicurus] |
| Full Idea: Nothing comes into being from what is not. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 38) | |
| A reaction: King Lear puts it better: Nothing will come of nothing [1.i]. There seems to be an underlying assumption that coming into being out of nothing is much weirder than just existing, but I am not convinced about that. It's all equally weird. |
| 14029 | If disappearing things went to nothingness, nothing could return, and it would all be gone by now [Epicurus] |
| Full Idea: If that which disappears were destroyed into what is not, all things would have been destroyed, since that into which they were dissolved does not exist. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 39) | |
| A reaction: This follows on from Idea 14028. Theologians will immediately spot that this is the underlying principle cited by Aquinas in his Third Way for proving God's existence (Idea 1431). |
| 14030 | The totality is complete, so there is no room for it to change, and nothing extraneous to change it [Epicurus] |
| Full Idea: The totality of things has always been just like it is now and always will be. For there is nothing for it to change into. For there exists nothing in addition to the totality, which could enter into it and produce the change. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 39) | |
| A reaction: This smacks of the sort of dubious arguments that the medieval theologians fell in love with. I never thought I'd say this, but I think Epicurus needs a comprehensive course in set theory before he makes remarks like this. |
| 14048 | Astronomical movements are blessed, but they don't need the help of the gods [Epicurus] |
| Full Idea: Movements, turnings, risings, settings, and related phenomena occur without any god helping out and ordaining or being about to ordain things, and at the same time have complete blessedness and indestructibility. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 76) | |
| A reaction: Epicurus is sometimes accused of atheism for remarks like these, but he is always trying to show piety in his attitudes. We might now call this attitude 'deism' (see alphabetical themes). |
| 14044 | The perceived accidental properties of bodies cannot be conceived of as independent natures [Epicurus] |
| Full Idea: The shapes, colours, sizes and weights which are predicated of body as accidents, ...and are known by sense-perception, must not be thought of as independent natures (for that is inconceivable). | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 68) | |
| A reaction: I take this to be an anti-platonist remark, though he is not denying that the accidental properties may have some universal character. I'm struck by how close the basic metaphysics of Epicurus is to that of Aristotle. |
| 14045 | Accidental properties give a body its nature, but are not themselves bodies or parts of bodies [Epicurus] |
| Full Idea: Accidental qualities are not non-existent, nor are they distinct corporeal entities inhering in the body, nor parts of it. We should think that the whole body throughout derives its permanent nature from these properties, though not as a compound of them. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 69) | |
| A reaction: 'Permanent' nature sounds more like essential than accidental properties. This is uncomfortably negative in its attempt to pin down what accidental properties are. The last bit seems to deny the bundle view of objects. Would he like tropes? |
| 16744 | All powers can be explained by obvious features like size, shape and motion of matter [Descartes] |
| Full Idea: There are no powers in stones and plants that are not so mysterious that they cannot be explained …from principles that are known to all and admitted by all, namely the shape, size, position, and motion of particles of matter. | |
| From: René Descartes (Principles of Philosophy [1646], IV.187), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 23.6 | |
| A reaction: This is an invocation of 'categorical' properties, against dispositions. I take this to be quite wrong. The explanation goes the other way. What supports the structures; what drives the motion; what initiates anything? |
| 14296 | Dispositions are physical states of mechanism; when known, these replace the old disposition term [Quine] |
| Full Idea: Each disposition, in my view, is a physical state or mechanism. ...In some cases nowadays we understand the physical details and set them forth explicitly in terms of the arrangement and interaction of small bodies. This replaces the old disposition. | |
| From: Willard Quine (The Roots of Reference [1990], p.11), quoted by Stephen Mumford - Dispositions 01.3 | |
| A reaction: A challenge to the dispositions and powers view of nature, one which rests on the 'categorical' structural properties, rather than the 'hypothetical' dispositions. But can we define a mechanism without mentioning its powers? |
| 5016 | Five universals: genus, species, difference, property, accident [Descartes] |
| Full Idea: The five commonly enumerated universals are: genus, species, difference, property and accident. | |
| From: René Descartes (Principles of Philosophy [1646], I.59) | |
| A reaction: Interestingly, this seems to be Descartes passing on his medieval Aristotelian inheritance, in which things are defined by placing them in a class, and then noting what distinguishes them within that class. |
| 5015 | A universal is a single idea applied to individual things that are similar to one another [Descartes] |
| Full Idea: Universals arise solely from the fact that we avail ourselves of one idea in order to think of all individual things that have a certain similitude. When we understand under the same name all the objects represented by this idea, that name is universal. | |
| From: René Descartes (Principles of Philosophy [1646], I.59) | |
| A reaction: Judging by the boldness of the pronouncement, it looks as if Descartes hasn't recognised the complexity of the problem. How do we spot a 'similarity', especially an abstraction like 'tool' or 'useful'? This sounds like Descartes trying to avoid Platonism. |
| 14046 | A 'body' is a conception of an aggregate, with properties defined by application conditions [Epicurus] |
| Full Idea: Properties are known by their peculiar forms of application and comprehension, in close accompaniment with the aggregate [of atoms], which is given the predicate 'body' by reference to the aggregate conception. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 69) | |
| A reaction: There is an interesting hint here of how to think of properties (as both applying and comprehended in some distinctive way), and a suggestion that there is something conventional about bodies, depending on how we conceive them. |
| 16630 | If we perceive an attribute, we infer the existence of some substance [Descartes] |
| Full Idea: Based on perceiving the presence of some attribute, we conclude there must also be present an existing thing or substance to which it can be attributed. | |
| From: René Descartes (Principles of Philosophy [1646], I.52), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 08.1 | |
| A reaction: A rainbow might be a tricky case. This illustrates the persistent belief in substances, even among philosophers who embraced the new corpuscular and mechanistic view of matter. |
| 5013 | A substance needs nothing else in order to exist [Descartes] |
| Full Idea: By substance we can understand nothing else than a thing which so exists that it needs no other thing in order to exist. | |
| From: René Descartes (Principles of Philosophy [1646], I.51) | |
| A reaction: Properties, of course, are the things which have dependent existence. Can properties be reduced to substances (e.g. by adopting a materialist theory of mind)? Note that Descartes does not think that substances depend on God for existence. |
| 14047 | Bodies have impermanent properties, and permanent ones which define its conceived nature [Epicurus] |
| Full Idea: Impermanent properties do not have the nature of an entire thing, which we call a body when we grasp it in aggregate, nor the nature of permanent accompaniments without which it is not possible to conceive of a body. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 70) | |
| A reaction: Epicurus doesn't discuss essences, but this seems to commit to the basic Aristotelian idea, that there there are some properties which actually bestow identity, and then others which are optional for that thing. The 'conception' is always mentioned. |
| 16633 | A substance has one principal property which is its nature and essence [Descartes] |
| Full Idea: Each substance has one principal property that constitutes its nature and essence, to which all its other properties are referred. Extension in length, breadth, and depth constitutes the nature of corporeal substance; and thought of thinking substances. | |
| From: René Descartes (Principles of Philosophy [1646], I.53), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 08.3 | |
| A reaction: Property is likely to be 'propria', which is a property distinctive of some thing, not just any old modern property. This is quite a strikingly original view of the nature of essence. Descartes despised 'substantial forms'. |
| 14039 | Above and below us will never appear to be the same, because it is inconceivable [Epicurus] |
| Full Idea: What is over our heads ...or what is below any point which we think of ...will never appear to us as being at the same time and in the same respect both up and down. For it is impossible to conceive of this. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 60) | |
| A reaction: Note that he says it will 'never appear to us' as both - not that it absolutely cannot be both. Both Aristotle and Epicurus are much more focused on how our humanity shapes our metaphysics than the modern pure metaphysicians are. |
| 14050 | We aim to dissolve our fears, by understanding their causes [Epicurus] |
| Full Idea: If we give a correct and complete causal account of the source of our disturbance and fears, we will dissolve them, by accounting for the phenomena to which we are constantly exposed, and which terrify other men most severely. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 82) | |
| A reaction: Notice 'other' men! This eudaimonist aim lies at the heart of Epicurus's physical account of the world. He was primarily interested in living better, rather than in physical science. He seeks 'tranquillity' and 'freedom from disturbance'. |
| 3658 | Total doubt can't include your existence while doubting [Descartes] |
| Full Idea: He who decides to doubt everything cannot nevertheless doubt that he exists while he doubts. | |
| From: René Descartes (Principles of Philosophy [1646], Pref) |
| 5005 | I think, therefore I am, because for a thinking thing to not exist is a contradiction [Descartes] |
| Full Idea: There is a contradiction in conceiving that what thinks does not (at the same time as it thinks) exist. Hence this conclusion I think, therefore I am, is the first and most certain that occurs to one who philosophises in an orderly way. | |
| From: René Descartes (Principles of Philosophy [1646], I.07) | |
| A reaction: The classic statement of his argument. The significance here is that it seems to have the structure of an argument, as it involves 'philosophising', which leads to a 'contradiction', and hence to the famous conclusion. It is not just intuitive. |
| 5006 | 'Thought' is all our conscious awareness, including feeling as well as understanding [Descartes] |
| Full Idea: By the word 'thought' I understand everything we are conscious of as operating in us. And that is why not only understanding, willing, imagining, but also feeling, are here the same thing as thinking. | |
| From: René Descartes (Principles of Philosophy [1646], I.09) | |
| A reaction: There is a bit of tension here between Descartes' correct need to include feeling in thought for his Cogito argument, and his tendency to dismiss animal consciousness, on the grounds that they only sense things, and don't make judgements. |
| 5012 | 'Nothing comes from nothing' is an eternal truth found within the mind [Descartes] |
| Full Idea: The proposition 'nothing comes from nothing' is not to be considered as an existing thing, or the mode of a thing, but as a certain eternal truth which has its seat in our mind and is a common notion or axiom. | |
| From: René Descartes (Principles of Philosophy [1646], I.49) | |
| A reaction: There is a tension here, in his assertion that it is 'eternal', but 'not existing'. How does one distinguish an innate idea from an innate truth? 'Eternal' sounds like an external guarantee of truth, but being 'in our mind' sounds less reliable. |
| 14037 | Atoms only have shape, weight and size, and the properties which accompany shape [Epicurus] |
| Full Idea: One must believe that the atoms bring with them none of the qualities of things which appear except shape, weight, and size and the properties which necessarily accompany shape. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 54) | |
| A reaction: This appears to be fairly precisely a claim that atoms only have primary qualities, though that terminology only came in in the seventeenth century. I take the view to be more or less correct. |
| 5004 | We can know basic Principles without further knowledge, but not the other way round [Descartes] |
| Full Idea: It is on the Principles, or first causes, that the knowledge of other things depends, so the Principles can be known without these last, but the other things cannot reciprocally be known without the Principles. | |
| From: René Descartes (Principles of Philosophy [1646], Pref) | |
| A reaction: A particularly strong assertion of foundationalism, as it says that not only must the foundations exist, but also we must actually know them. This sounds false, as elementary knowledge then seems to require far too much sophistication. |
| 6010 | Illusions are not false perceptions, as we accurately perceive the pattern of atoms [Epicurus, by Modrak] |
| Full Idea: Epicurus says illusions are not false perceptions, because the senses accurately report the pattern of atoms; for instance, the edges are worn off the pattern produced by a square tower, so its perception as a round tower is true. | |
| From: report of Epicurus (Letter to Herodotus [c.293 BCE], 47-53) by Deborah K.W. Modrak - Classical theories of Mind | |
| A reaction: As so often, Epicurus got it right, because Democritus got it right, thus demonstrating that good philosophy must be preceded by good physics. However, good physics must be preceded and followed by good philosophy. |
| 14041 | The soul is fine parts distributed through the body, resembling hot breath [Epicurus] |
| Full Idea: The soul is a body made up of fine parts distributed throught the entire aggregate, most closely resembling breath with a certain admixture of heat, in one way resembling breath and in another resembling heat | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 63) | |
| A reaction: Remember that 'psuché' refers as much to the life within a creature as it does to the consciousness. The stoics seem to have held a similar view. |
| 5014 | We can understand thinking occuring without imagination or sensation [Descartes] |
| Full Idea: We can understand thinking without imagination or sensation, as is quite clear to anyone who attends to the matter. | |
| From: René Descartes (Principles of Philosophy [1646], I.53) | |
| A reaction: We may certainly take it that Descartes means if it is understandable then it is logically possible. To believe that thinking could occur without imagination strikes me as an astonishing error. I take imagination to be more central than understanding. |
| 5017 | In thinking we shut ourselves off from other substances, showing our identity and separateness [Descartes] |
| Full Idea: Because each one of us understands what he thinks, and that in thinking he can shut himself off from every other substance, we may conclude that each of us is really distinct from every other thinking substance and from corporeal substance. | |
| From: René Descartes (Principles of Philosophy [1646], I.60) | |
| A reaction: This seems to be a novel argument which requires elucidation. I can 'shut myself off from every other substance'? If I shut myself off from thinking about food, does that mean hunger is not part of me? Or convince yourself that you don't have a brother? |
| 5010 | Our free will is so self-evident to us that it must be a basic innate idea [Descartes] |
| Full Idea: It is so evident that we are possessed of a free will that can give or withhold its assent, that this may be counted as one of the first and most common notions found innately in us. | |
| From: René Descartes (Principles of Philosophy [1646], I.39) | |
| A reaction: It seems to me plausible to say that we have an innate conception of our own will (our ability to make decisions), though Hume says we only learn about the will from experience, but the idea that it is absolutely 'free' might never cross our minds. |
| 5011 | There are two ultimate classes of existence: thinking substance and extended substance [Descartes] |
| Full Idea: I observe two ultimate classes of things: intellectual or thinking things, pertaining to the mind or to thinking substance, and material things, pertaining to extended substance or to body. | |
| From: René Descartes (Principles of Philosophy [1646], I.48) | |
| A reaction: This is clear confirmation that Descartes believed the mind is a substance, rather than an insubstantial world of thinking. It leaves open the possibility of a different theory: that mind is not a substance, but is a Platonic adjunct to reality. |
| 5018 | Even if tightly united, mind and body are different, as God could separate them [Descartes] |
| Full Idea: Even if we suppose God had united a body and a soul so closely that they couldn't be closer, and made a single thing out of the two, they would still remain distinct, because God has the power of separating them, or conserving out without the other. | |
| From: René Descartes (Principles of Philosophy [1646], I.60) | |
| A reaction: If Descartes lost his belief in God (after discussing existence with Kant) would he cease to be a dualist? This quotation seems to be close to conceding a mind-body relationship more like supervenience than interaction. |
| 14042 | The soul cannot be incorporeal, because then it could neither act nor be acted upon [Epicurus] |
| Full Idea: Those who say that the soul is incorporeal are speaking to no point; for if it were of that character, it could neither act nor be acted upon at all. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 67) | |
| A reaction: This just is the causal argument, which is espoused by Papineau and other modern physicalists. Personally I am inclined to agree with Papineau, that it is so simple and conclusive that it is hardly worth discussing further. Dualism needs a miracle. |
| 5007 | Most errors of judgement result from an inaccurate perception of the facts [Descartes] |
| Full Idea: What usually misleads us is that we very frequently form a judgement although we do not have an accurate perception of what we judge. | |
| From: René Descartes (Principles of Philosophy [1646], I.33) | |
| A reaction: This seems to me a generally accurate observation, particularly in the making of moral judgements (which was probably not what Descartes was considering). The implication is that judgements are to a large extent forced by our perceptions. |
| 5009 | We do not praise the acts of an efficient automaton, as their acts are necessary [Descartes] |
| Full Idea: We do not praise automata, although they respond exactly to the movements they were designed to produce, since their actions are performed necessarily | |
| From: René Descartes (Principles of Philosophy [1646], I.37) | |
| A reaction: I say we attribute responsibility when we perceive something like a 'person' as causing them. We don't blame small animals, because there is 'no one at home', but we blame children as they develop a full character and identity. We can ignore free will. |
| 5008 | The greatest perfection of man is to act by free will, and thus merit praise or blame [Descartes] |
| Full Idea: That the will should extend widely accords with its nature, and it is the greatest perfection in man to be able to act by its means, that is, freely, and by so doing we are in peculiar way masters of our actions, and thereby merit praise or blame. | |
| From: René Descartes (Principles of Philosophy [1646], I.37) | |
| A reaction: This seems to me to be a deep-rooted and false understanding which philosophy has inherited from theology. It doesn't strike me that there must an absolute 'buck-stop' to make us responsible. Why is it better for a decision to appear out of nowhere? |
| 15987 | Physics only needs geometry or abstract mathematics, which can explain and demonstrate everything [Descartes] |
| Full Idea: I do not accept or desire any other principle in physics than in geometry or abstract mathematics, because all the phenomena of nature may be explained by their means, and sure demonstrations can be given of them. | |
| From: René Descartes (Principles of Philosophy [1646], 2.64), quoted by Peter Alexander - Ideas, Qualities and Corpuscles 7 | |
| A reaction: This is his famous and rather extreme view, which might be described as hyper-pythagoreanism (by adding geometry to numbers). It seems to leave out matter, forces and activity. |
| 12730 | We will not try to understand natural or divine ends, or final causes [Descartes] |
|
Full Idea:
We will not seek for the reason of natural things from the end which God or nature has set before him in their creation |
|
| From: René Descartes (Principles of Philosophy [1646], §28) | |
| A reaction: Teleology is more relevant to biology than to the other sciences, and it is hard to understand an eye without a notion of 'what it is for'. Planetary motion reveals nothing about purposes. If you demand a purpose, it becomes more baffling. |
| 14032 | Totality has no edge; an edge implies a contrast beyond the edge, and there can't be one [Epicurus] |
| Full Idea: The totality is unlimited. For what is limited has an extreme; but an extreme is seen in contrast to something else, so that since it has no extreme it has no limit. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 41) | |
| A reaction: I presume that the 'limit' is the edge, and the 'extreme' is what is beyond the edge. Why could not the extreme be nothingness, which then contrast dramatically with what exists? |
| 14033 | Bodies are unlimited as well as void, since the two necessarily go together [Epicurus] |
| Full Idea: The number of bodies and the magnitude of the void are unlimited. If void were unlimited, and bodies limited, bodies move in scattered fashion with no support of checking collisions; in limited void, unlimited bodies would not have a place to be in. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 42) | |
| A reaction: Seems good. The point is that without collisions, bodies would not stop relative to one another, and combine to form the objects we perceive. Of course if the started off (anathema!) stuck together, they may not have dispersed yet. |
| 14034 | There exists an infinity of each shape of atom, but the number of shapes is beyond our knowledge [Epicurus] |
| Full Idea: For each type of shape there is an unlimited number of similar atoms, but with respect to the differences they are not simply unlimited but ungraspable. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 42) | |
| A reaction: Epicurus's view of the nature of atoms rests on his empiricism, so while he can reason from experience to how they must be, he admits (impressively) his ignorance of the full facts. He has arguments for the unlimited number. |
| 14035 | Atoms just have shape, size and weight; colour results from their arrangement [Epicurus] |
| Full Idea: There are not even any qualities in atoms, except shape and size and weight; their colour changes according to the arrangement of the atoms. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 44 schol) | |
| A reaction: [This is quoted by a 'scholiast' - an early writer quoting from Epicurus's '12 Basic Principles'] He appears to have got this one wrong, as it is evidently the type of atom, as well as the arrangement, which contributes to the colour. |
| 14038 | There cannot be unlimited division, because it would reduce things to non-existence [Epicurus] |
| Full Idea: One must eliminate unlimited division into smaller pieces (to avoid making everything weak and being forced in our comprehensive grasps of compound things to exhaust the things which exist by reducing them to non-existence). | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 56) | |
| A reaction: A basic argument for atoms, but it seems to rest on Zenonian paradoxes about infinite subdivision. An infinite subdivision of a unit doesn't seem to turn it into zero. |
| 16601 | Matter is not hard, heavy or coloured, but merely extended in space [Descartes] |
| Full Idea: The nature of matter, or body viewed as a whole, consists not in its being something which is hard, heavy, or colored, or which in any other way affects the senses, but only in its being a thing extended in length, breadth and depth. | |
| From: René Descartes (Principles of Philosophy [1646], 2.4), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 04.5 |
| 14049 | We aim to know the natures which are observed in natural phenomena [Epicurus] |
| Full Idea: Blessedness lies in knowing the natures which are observed in meteorological phenomena. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 78) | |
| A reaction: This pursuit of 'natures' seems to be at the heart of scientific essentialism. Epicurus demonstrates his proposal, by offering speculations about the natures of all sorts of phenomena (esp. in 'Letter to Pythocles'). |
| 14043 | The void cannot interact, but just gives the possibility of motion [Epicurus] |
| Full Idea: The void can neither act nor be acted upon but merely provides the possibility of motion through itself for bodies. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 67) | |
| A reaction: Epicurus follows this with the anti-dualist Idea 14042, but he is at least offering the notion of something which exists without powers of causal interaction. Does space undermine the causal criterion for existence? |
| 14031 | Space must exist, since movement is obvious, and there must be somewhere to move in [Epicurus] |
| Full Idea: If there did not exist that which we call void and space and intangible nature, bodies would not have any place to be in or move through, as they obviously do move. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 40) | |
| A reaction: The observation that 'they obviously do move' must be aimed at followers of Parmenides. The idea of the void seems to contain a Newtonian commitment to absolute space. |
| 14036 | There are endless cosmoi, some like and some unlike this one [Epicurus] |
| Full Idea: There is an unlimited number of cosmoi, and some are similar to this one and some are dissimilar. | |
| From: Epicurus (Letter to Herodotus [c.293 BCE], 45) |