53 ideas
| 2056 | Philosophers are always switching direction to something more interesting [Plato] |
| Full Idea: Philosophers are always ready to change direction, if a topic crops up which is more attractive than the one to hand. | |
| From: Plato (Theaetetus [c.368 BCE], 172d) | |
| A reaction: Which sounds trivial, but it may be what God does. |
| 2086 | Understanding mainly involves knowing the elements, not their combinations [Plato] |
| Full Idea: A perfect grasp of any subject depends far more on knowing elements than on knowing complexes. | |
| From: Plato (Theaetetus [c.368 BCE], 206b) |
| 2083 | Either a syllable is its letters (making parts as knowable as whole) or it isn't (meaning it has no parts) [Plato] |
| Full Idea: Either a syllable is not the same as its letters, in which case it cannot have the letters as parts of itself, or it is the same as its letters, in which case these basic elements are just as knowable as it is. | |
| From: Plato (Theaetetus [c.368 BCE], 205b) |
| 2082 | A rational account is essentially a weaving together of things with names [Plato] |
| Full Idea: Just as primary elements are woven together, so their names may be woven together to produce a spoken account, because an account is essentially a weaving together of names. | |
| From: Plato (Theaetetus [c.368 BCE], 202b) | |
| A reaction: If justification requires 'logos', and logos is a 'weaving together of names', then Plato might be taken as endorsing the coherence account of justification. Or do the two 'weavings' correspond? |
| 4642 | No fact can be real and no proposition true unless there is a Sufficient Reason (even if we can't know it) [Leibniz] |
| Full Idea: The principle of sufficient reason says no fact can be real or existing and no proposition can be true unless there is a sufficient reason why it should be thus and not otherwise, even though in most cases these reasons cannot be known to us. | |
| From: Gottfried Leibniz (Monadology [1716], §32) | |
| A reaction: I think of this as my earliest philosophical perception, a childish rebellion against being told that there was 'no reason' for something. My intuition tells me that it is correct, and the foundation of ontology and truth. Don't ask me to justify it! |
| 2052 | Eristic discussion is aggressive, but dialectic aims to help one's companions in discussion [Plato] |
| Full Idea: Eristic discussions involve as many tricks and traps as possible, but dialectical discussions involve being serious and correcting the interlocutor's mistakes only when they are his own fault or the result of past conditioning. | |
| From: Plato (Theaetetus [c.368 BCE], 167e) |
| 15854 | A primary element has only a name, and no logos, but complexes have an account, by weaving the names [Plato] |
| Full Idea: A primary element cannot be expressed in an account; it can only be named, for a name is all that it has. But with the things composed of these ...just as the elements are woven together, so the names can woven to become an account. | |
| From: Plato (Theaetetus [c.368 BCE], 202b01-3) | |
| A reaction: This is the beginning of what I see as Aristotle's metaphysics, as derived from his epistemology, that is, ontology is what explains, and what we can give an account [logos] of. Aristotle treats this under 'definitions'. |
| 2115 | Everything in the universe is interconnected, so potentially a mind could know everything [Leibniz] |
| Full Idea: Every body is sensitive to everything in the universe, so that one who saw everything could read in each body what is happening everywhere, and even what has happened and will happen. | |
| From: Gottfried Leibniz (Monadology [1716], §61) |
| 2111 | Falsehood involves a contradiction, and truth is contradictory of falsehood [Leibniz] |
| Full Idea: We judge to be false that which involves a contradiction, and true that which is opposed or contradictory to the false. | |
| From: Gottfried Leibniz (Monadology [1716], §31) |
| 10216 | We master arithmetic by knowing all the numbers in our soul [Plato] |
| Full Idea: It must surely be true that a man who has completely mastered arithmetic knows all numbers? Because there are pieces of knowledge covering all numbers in his soul. | |
| From: Plato (Theaetetus [c.368 BCE], 198b) | |
| A reaction: This clearly views numbers as objects. Expectation of knowing them all is a bit startling! They also appear to be innate in us, and hence they appear to be Forms. See Aristotle's comment in Idea 645. |
| 2060 | There seem to be two sorts of change: alteration and motion [Plato] |
| Full Idea: There are two kinds of change, I think: alteration and motion. | |
| From: Plato (Theaetetus [c.368 BCE], 181d) | |
| A reaction: Idea 1700 is better than this. |
| 7644 | The monad idea incomprehensibly spiritualises matter, instead of materialising soul [La Mettrie on Leibniz] |
| Full Idea: The Leibnizians with their monads have constructed an incomprehensible hypothesis. They have spiritualized matter rather than materialising the soul. | |
| From: comment on Gottfried Leibniz (Monadology [1716]) by Julien Offray de La Mettrie - Machine Man p.3 | |
| A reaction: I agree with La Mettrie. This disagreement shows, I think, how important the problem of interaction between mind and body was in the century after Descartes. Drastic action seemed needed to bridge the gap, one way or the other. |
| 11857 | He replaced Aristotelian continuants with monads [Leibniz, by Wiggins] |
| Full Idea: In the end Leibniz dethroned Aristotelian continuants, seen as imperfect from his point of view, in favour of monads. | |
| From: report of Gottfried Leibniz (Monadology [1716]) by David Wiggins - Sameness and Substance Renewed 3.1 | |
| A reaction: I take the 'continuants' to be either the 'ultimate subject of predication' (in 'Categories'), or 'essences' (in 'Metaphysics'). Since monads seem to be mental (presumably to explain the powers of things), this strikes me as a bit mad. |
| 7843 | Is a drop of urine really an infinity of thinking monads? [Voltaire on Leibniz] |
| Full Idea: Can you really maintain that a drop of urine is an infinity of monads, and that each one of these has ideas, however obscure, of the entire universe? | |
| From: comment on Gottfried Leibniz (Monadology [1716]) by Francois-Marie Voltaire - works Vol 22:434 | |
| A reaction: Monads are a bit like Christian theology - if you meet them cold they seem totally ridiculous, but if you meet them after ten years of careful preliminary study they make (apparently) complete sense. Defenders of panpsychism presumably like them. |
| 12751 | It is unclear in 'Monadology' how extended bodies relate to mind-like monads. [Garber on Leibniz] |
| Full Idea: It is never clear in the 'Monadologie' how exactly the world of extended bodies is related to the world of simple substances, the world of non-extended and mind-like monads. | |
| From: comment on Gottfried Leibniz (Monadology [1716]) by Daniel Garber - Leibniz:Body,Substance,Monad 9 | |
| A reaction: Leibniz was always going to hit the interaction problem, as soon as he started giving an increasingly spiritual account of what a substance, and hence marginalising the 'force' which had held centre-stage earlier on. Presumably they are 'parallel'. |
| 19363 | Changes in a monad come from an internal principle, and the diversity within its substance [Leibniz] |
| Full Idea: A monad's natural changes come from an internal principle, ...but there must be diversity in that which changes, which produces the specification and variety of substances. | |
| From: Gottfried Leibniz (Monadology [1716], §11-12) | |
| A reaction: You don't have to like monads to like this generalisation (and Perkins says Leibniz had a genius for generalisations). Metaphysics must give an account of change. Succeeding time-slices etc explain nothing. Principle and substance must meet. |
| 19352 | A 'monad' has basic perception and appetite; a 'soul' has distinct perception and memory [Leibniz] |
| Full Idea: The general name 'monad' or 'entelechy' may suffice for those substances which have nothing but perception and appetition; the name 'souls' may be reserved for those having perception that is more distinct and accompanied by memory. | |
| From: Gottfried Leibniz (Monadology [1716], §19) | |
| A reaction: It is basic to the study of Leibniz that you don't think monads are full-blown consciousnesses. He isn't really a panpsychist, because the level of mental activity is so minimal. There seem to be degrees of monadhood. |
| 7931 | If a substance is just a thing that has properties, it seems to be a characterless non-entity [Leibniz, by Macdonald,C] |
| Full Idea: For Leibniz, to distinguish between a substance and its properties in order to provide a thing or entity in which properties can inhere leads necessarily to the absurd conclusion that the substance itself must be a truly characterless non-entity. | |
| From: report of Gottfried Leibniz (Monadology [1716]) by Cynthia Macdonald - Varieties of Things Ch.3 | |
| A reaction: This is obviously one of the basic thoughts in any discussion of substances. It is why physicists ignore them, and Leibniz opted for a 'bundle' theory. But the alternative seems daft too - free-floating properties, hooked onto one another. |
| 2084 | If a word has no parts and has a single identity, it turns out to be the same kind of thing as a letter [Plato] |
| Full Idea: If a complex or a syllable has no parts and is a single identity, hasn't it turned out to be the same kind of thing as an element or letter? | |
| From: Plato (Theaetetus [c.368 BCE], 205d) |
| 15844 | A sum is that from which nothing is lacking, which is a whole [Plato] |
| Full Idea: But this sum now - isn't it just when there is nothing lacking that it is a sum? Yes, necessarily. And won't this very same thing - that from which nothing is lacking - be a whole? | |
| From: Plato (Theaetetus [c.368 BCE], 205a) | |
| A reaction: This seems to be right, be rather too vague and potentially circular to be of much use. What is the criterion for deciding that nothing is lacking? |
| 15843 | The whole can't be the parts, because it would be all of the parts, which is the whole [Plato] |
| Full Idea: The whole does not consist of parts; for it did, it would be all the parts and so would be the sum. | |
| From: Plato (Theaetetus [c.368 BCE], 204e) | |
| A reaction: That is, 'the whole is the sum of its parts' is a tautology! The claim that 'the whole is more than the sum of its parts' gets into similar trouble. See Verity Harte on this. |
| 17554 | There must be some internal difference between any two beings in nature [Leibniz] |
| Full Idea: There are never two beings in nature that are perfectly alike, two beings in which it is not possible to discover an internal difference, that is, one founded on an intrinsic denomination. | |
| From: Gottfried Leibniz (Monadology [1716], §09) | |
| A reaction: From this it follows that if two things really are indiscernible, then we must say that they are one thing. He says monads all differ from one another. People certainly do. Leibniz must say this of electrons. How can he know this? |
| 2112 | Truths of reason are known by analysis, and are necessary; facts are contingent, and their opposites possible [Leibniz] |
| Full Idea: There are two kinds of truths: of reasoning and of facts. Truths of reasoning are necessary and their opposites impossible. Facts are contingent and their opposites possible. A necessary truth is known by analysis. | |
| From: Gottfried Leibniz (Monadology [1716], §33) |
| 2080 | Things are only knowable if a rational account (logos) is possible [Plato] |
| Full Idea: Things which are susceptible to a rational account are knowable. | |
| From: Plato (Theaetetus [c.368 BCE], 201d) |
| 16126 | Expertise is knowledge of the whole by means of the parts [Plato] |
| Full Idea: A man has passed from mere judgment to expert knowledge of the being of a wagon when he has done so in virtue of having gone over the whole by means of the elements. | |
| From: Plato (Theaetetus [c.368 BCE], 207c) | |
| A reaction: Plato is emphasising that the expert must know the hundred parts of a wagon, and not just the half dozen main components, but here the point is to go over the whole via the parts, and not just list the parts. |
| 2050 | It is impossible to believe something which is held to be false [Plato] |
| Full Idea: It is impossible to believe something which is not the case. | |
| From: Plato (Theaetetus [c.368 BCE], 167a) |
| 2076 | How can a belief exist if its object doesn't exist? [Plato] |
| Full Idea: If the object of a belief is what is not, the object of this belief is nothing; but if there is no object to a belief, then that is not belief at all. | |
| From: Plato (Theaetetus [c.368 BCE], 189a) |
| 9344 | Mathematical analysis ends in primitive principles, which cannot be and need not be demonstrated [Leibniz] |
| Full Idea: At the end of the analytical method in mathematics there are simple ideas of which no definition can be given. Moreover there are axioms and postulates, in short, primitive principles, which cannot be demonstrated and do not need demonstration. | |
| From: Gottfried Leibniz (Monadology [1716], §35) | |
| A reaction: My view is that we do not know such principles when we apprehend them in isolation. I would call them 'intuitions'. They only ascend to the status of knowledge when the mathematics is extended and derived from them, and found to work. |
| 2045 | Perception is infallible, suggesting that it is knowledge [Plato] |
| Full Idea: Perception is always of something that is, and it is infallible, which suggests that it is knowledge. | |
| From: Plato (Theaetetus [c.368 BCE], 152c) |
| 2067 | Our senses could have been separate, but they converge on one mind [Plato] |
| Full Idea: It would be peculiar if each of us were like a Trojan horse, with a whole bunch of senses sitting inside us, rather than that all these perceptions converge onto a single identity (mind, or whatever one ought to call it). | |
| From: Plato (Theaetetus [c.368 BCE], 184d) |
| 2068 | With what physical faculty do we perceive pairs of opposed abstract qualities? [Plato] |
| Full Idea: With what physical faculty do we perceive being and not-being, similarity and dissimilarity, identity and difference, oneness and many, odd and even and other maths, ….fineness and goodness? | |
| From: Plato (Theaetetus [c.368 BCE], 185d) |
| 2069 | Thought must grasp being itself before truth becomes possible [Plato] |
| Full Idea: If you can't apprehend being you can't apprehend truth, and so a thing could not be known. Therefore knowledge is not located in immediate experience but in thinking about it, since the latter makes it possible to grasp being and truth. | |
| From: Plato (Theaetetus [c.368 BCE], 186c) |
| 2110 | We all expect the sun to rise tomorrow by experience, but astronomers expect it by reason [Leibniz] |
| Full Idea: When we expect it to be day tomorrow, we all behave as empiricists, because until now it has always happened thus. The astronomer alone knows this by reason. | |
| From: Gottfried Leibniz (Monadology [1716], §28) |
| 2078 | You might mistake eleven for twelve in your senses, but not in your mind [Plato] |
| Full Idea: Sight or touch might make someone take eleven for twelve, but he could never form this mistaken belief about the contents of his mind. | |
| From: Plato (Theaetetus [c.368 BCE], 195e) |
| 2089 | An inadequate rational account would still not justify knowledge [Plato] |
| Full Idea: If you don't know which letters belong together in the right syllables…it is possible for true belief to be accompanied by a rational account and still not be entitled to the name of knowledge. | |
| From: Plato (Theaetetus [c.368 BCE], 208b) | |
| A reaction: In each case of justification there is a 'clinching' stage, for which there is never going to be a strict rule. It might be foundational, but equally it might be massive coherence, or no alternative. |
| 2085 | Parts and wholes are either equally knowable or equally unknowable [Plato] |
| Full Idea: Either a syllable and its letters are equally knowable and expressible in a rational account, or they are both equally unknowable and inexpressible. | |
| From: Plato (Theaetetus [c.368 BCE], 205e) | |
| A reaction: Presumably you could explain the syllable by the letters, but not vice versa, but he must mean that the explanation is worthless without the letters being explained too. So all explanation is worthless? |
| 2091 | Without distinguishing marks, how do I know what my beliefs are about? [Plato] |
| Full Idea: If I only have beliefs about Theaetetus when I don't know his distinguishing mark, how on earth were my beliefs about you rather than anyone else? | |
| From: Plato (Theaetetus [c.368 BCE], 209b) | |
| A reaction: This is a rather intellectualist approach to mental activity. Presumably Theaetetus has lots of distinguishing marks, but they are not conscious. Must Socrates know everything? |
| 2087 | A rational account might be seeing an image of one's belief, like a reflection in a mirror [Plato] |
| Full Idea: A rational account might be forming an image of one's belief, as in a mirror or a pond. | |
| From: Plato (Theaetetus [c.368 BCE], 206d) | |
| A reaction: Not promising, since the image is not going to be clearer than the original, or contain any new information. Maybe it would be clarified by being 'framed', instead of drifting in muddle. |
| 2090 | A rational account involves giving an image, or analysis, or giving a differentiating mark [Plato] |
| Full Idea: A third sort of rational account (after giving an image, or analysing elements) is being able to mention some mark which differentiates the object in question ('the sun is the brightest heavenly body'). | |
| From: Plato (Theaetetus [c.368 BCE], 208c) | |
| A reaction: This is Plato's clearest statement of what would be involved in adding the necessary logos to your true belief. An image of it, or an analysis, or an individuation. How about a cause? |
| 2081 | Maybe primary elements can be named, but not receive a rational account [Plato] |
| Full Idea: Maybe the primary elements of which things are composed are not susceptible to rational accounts. Each of them taken by itself can only be named, but nothing further can be said about it. | |
| From: Plato (Theaetetus [c.368 BCE], 201e) | |
| A reaction: This still seems to be more or less the central issue in philosophy - which things should be treated as 'primitive', and which other things are analysed and explained using the primitive tools? |
| 2088 | A rational account of a wagon would mean knowledge of its hundred parts [Plato] |
| Full Idea: In the case of a wagon, we may only have correct belief, but someone who is able to explain what it is by going through its hundred parts has got hold of a rational account. | |
| From: Plato (Theaetetus [c.368 BCE], 207b) | |
| A reaction: A wonderful example. In science, you know smoking correlates with cancer, but you only know it when you know the mechanism, the causal structure. This may be a general truth. |
| 2047 | What evidence can be brought to show whether we are dreaming or not? [Plato] |
| Full Idea: What evidence could be brought if we were asked at this very moment whether we are asleep and are dreaming all our thoughts? | |
| From: Plato (Theaetetus [c.368 BCE], 158b) |
| 2054 | Clearly some people are superior to others when it comes to medicine [Plato] |
| Full Idea: In medicine, at least, most people are not self-sufficient at prescribing and effecting cures for themselves, and here some people are superior to others. | |
| From: Plato (Theaetetus [c.368 BCE], 171e) |
| 2059 | How can a relativist form opinions about what will happen in the future? [Plato] |
| Full Idea: Does a relativist have any authority to decide about things which will happen in the future? | |
| From: Plato (Theaetetus [c.368 BCE], 178c) | |
| A reaction: Nice question! It seems commonsense that such speculations are possible, but without a concept of truth they are ridiculous. |
| 2053 | If you claim that all beliefs are true, that includes beliefs opposed to your own [Plato] |
| Full Idea: To say that everyone believes what is the case, is to concede the truth of the oppositions' beliefs; in other words, the person has to concede that he himself is wrong. | |
| From: Plato (Theaetetus [c.368 BCE], 171a) |
| 2109 | Increase a conscious machine to the size of a mill - you still won't see perceptions in it [Leibniz] |
| Full Idea: If a conscious machine were increased in size, one might enter it like a mill, but we should only see the parts impinging on one another; we should not see anything which would explain a perception. | |
| From: Gottfried Leibniz (Monadology [1716], §17) | |
| A reaction: A wonderful image for capturing a widely held intuition. It seems to motivate Colin McGinn's 'Mysterianism'. The trouble is Leibniz didn't think big/small enough. Down at the level of molecules it might become obvious what a perception is. 'Might'. |
| 19362 | We know the 'I' and its contents by abstraction from awareness of necessary truths [Leibniz] |
| Full Idea: It is through the knowledge of necessary truths and through their abstraction that we rise to reflective acts, which enable us to think of that which is called "I" and enable us to consider that this or that is in us. | |
| From: Gottfried Leibniz (Monadology [1716], §30) | |
| A reaction: For Leibniz, necessary truth can only be known a priori. Sense experience won't reveal the self, as Hume observed. We evidently 'abstract' the idea of 'I' from the nature of a priori thought. Animals have no self (or morals) for this reason. |
| 20444 | If paintings could be perfectly duplicated, it would be a multiple art form [Currie, by Bacharach] |
| Full Idea: Currie claims that, in principle, all art forms are multiple. A superxerox machine, duplicating a painting molecule by molecule, would show that paintings are singular only contingently. | |
| From: report of Gregory Currie (An Ontology of Art [1988]) by Sondra Bacharach - Arthur C. Danto 3 | |
| A reaction: This strikes me as correct. An original painting would then have the same status as the manuscript of a poem, giving it an authority, and being moving by its personal contact with the artist. But worth far less than current original paintings. |
| 12707 | The true elements are atomic monads [Leibniz] |
| Full Idea: Monads are the true atoms of nature and, in brief, the elements of things. | |
| From: Gottfried Leibniz (Monadology [1716], (opening)), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 2 | |
| A reaction: Thus in one sentence Leibniz gives us a theory of natural elements, and an account of atoms. This kind of speculation got metaphysics a bad name when science unravelled a more accurate picture. The bones must be picked out of Leibniz. |
| 2114 | This is the most perfect possible universe, in its combination of variety with order [Leibniz] |
| Full Idea: From all the possible universes God chooses this one to obtain as much variety as possible, but with the greatest order possible; that is, it is the means of obtaining the greatest perfection possible. | |
| From: Gottfried Leibniz (Monadology [1716], §58) |
| 2058 | God must be the epitome of goodness, and we can only approach a divine state by being as good as possible [Plato] |
| Full Idea: It is impossible for God to be immoral and not to be the acme of morality; and the only way any of us can approximate to God is to become as moral as possible. | |
| From: Plato (Theaetetus [c.368 BCE], 176c) |
| 2113 | God alone (the Necessary Being) has the privilege that He must exist if He is possible [Leibniz] |
| Full Idea: God alone (or the Necessary Being) has the privilege that He must exist if He is possible. | |
| From: Gottfried Leibniz (Monadology [1716], §45) |
| 2057 | There must always be some force of evil ranged against good [Plato] |
| Full Idea: The elimination of evil is impossible, Theodorus; there must always be some force ranged against good. | |
| From: Plato (Theaetetus [c.368 BCE], 176a) |