48 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? |
| 19342 | Reason avoids multiplying hypotheses or principles [Leibniz] |
| Full Idea: Reason requires that we avoid multiplying hypotheses or principles, in somewhat the same way that the simplest system is always preferred in astronomy. | |
| From: Gottfried Leibniz (Discourse on Metaphysics [1686], 5) | |
| A reaction: He offers this principle without mentioning Ockham, as if it were self-evident. |
| 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'. |
| 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) |
| 15201 | That Queen Anne is dead is a 'general fact', not a fact about Queen Anne [Prior,AN] |
| Full Idea: The fact that Queen Anne has been dead for some years is not, in the strict sense of 'about', a fact about Queen Anne; it is not a fact about anyone or anything - it is a general fact. | |
| From: Arthur N. Prior (Changes in Events and Changes in Things [1968], p.13), quoted by Robin Le Poidevin - Past, Present and Future of Debate about Tense 1 b | |
| A reaction: He distinguishes 'general facts' (states of affairs, I think) from 'individual facts', involving some specific object. General facts seem to be what are expressed by negative existential truths, such as 'there is no Loch Ness Monster'. Useful. |
| 12711 | The immediate cause of movements is more real [than geometry] [Leibniz] |
| Full Idea: The force or proximate cause of these changes [of position] is something more real, and there is sufficient basis to attribute it to one body more than to another. | |
| From: Gottfried Leibniz (Discourse on Metaphysics [1686], §18), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 3 | |
| A reaction: The force is said to be 'more real' than geometry. Leibniz seems to have embraced fairly physical powers in the period 1678-1698, and then seen them as more and more like spirits. |
| 19349 | The complete notion of a substance implies all of its predicates or attributes [Leibniz] |
| Full Idea: The nature of an individual substance or of a complete being is to have a notion so complete that it is sufficient to contain and to allow us to deduce from it all the predicates of the subject to which this notion is attributed. | |
| From: Gottfried Leibniz (Discourse on Metaphysics [1686], §8) | |
| A reaction: This is the unusual Leibnizian view of such things, which he takes to extremes. I think it depends on whether you are talking of predicates, or of real intrinsic properties. I don't see how what happens to a substance can be contained in the subject. |
| 7558 | Substances mirror God or the universe, each from its own viewpoint [Leibniz] |
| Full Idea: Each substance is like a whole world, and like a mirror of God, or indeed of the whole universe, which each one expresses in its own fashion. | |
| From: Gottfried Leibniz (Discourse on Metaphysics [1686]), quoted by Nicholas Jolley - Leibniz Intro | |
| A reaction: Leibniz isn't a pantheist, so he does not identify God with the universe, so it is a bit revealing that substance could reflect either one or the other, and he doesn't seem to care which. In the end, for all the sophistication, he just made it up. |
| 16761 | Forms are of no value in physics, but are indispensable in metaphysics [Leibniz] |
| Full Idea: The consideration of forms serves no purpose in the details of physics and must not be used to explain particular phenomena. …but their misuse must not lead us to reject something which is so useful to metaphysics. | |
| From: Gottfried Leibniz (Discourse on Metaphysics [1686], 10), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 24.5 | |
| A reaction: This is a key test for the question of whether metaphysics is separate from science (as Leibniz and Pasnau think), or whether there is a continuum. Is 'substantial form' an illuminating way to undestand modern physics? |
| 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. |
| 13088 | Subjects include predicates, so full understanding of subjects reveals all the predicates [Leibniz] |
| Full Idea: The subject-term must always include the predicate-term, in such a way that the man who understood the notion of the subject perfectly would also judge that the predicate belongs to it. | |
| From: Gottfried Leibniz (Discourse on Metaphysics [1686], §8) | |
| A reaction: Sounds as if every sentence is analytic, but he doesn't mean that. He does, oddly, mean that if we fully understand the name 'Alexander', we understand his complete history, which is a bit silly, I'm afraid. Even God doesn't learn things just from names. |
| 13085 | Leibniz is some form of haecceitist [Leibniz, by Cover/O'Leary-Hawthorne] |
| Full Idea: Some form of haecceitism is central to the Leibnizian metaphysic. | |
| From: report of Gottfried Leibniz (Discourse on Metaphysics [1686], §8) by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 5.2.1 | |
| A reaction: That is, there is some inner hallmark that individuates each thing (though they don't mean the Duns Scotus idea of a haecceity which has no qualities apart from the capacity to individuate). Leibniz thinks essences individuate. |
| 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) |
| 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) |
| 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) |
| 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) |
| 5024 | Knowledge doesn't just come from the senses; we know the self, substance, identity, being etc. [Leibniz] |
| Full Idea: It is always false to say that all our notions come from the so-called external senses, for the notion I have of myself and of my thoughts, and consequently of being, substance, action, identity, and many others, come from an internal experience. | |
| From: Gottfried Leibniz (Discourse on Metaphysics [1686], §27) | |
| A reaction: Of course, an empiricist like Hume would not deny this, as he bases his views on 'experience' (including anger, for example), not just 'sense experience'. But Hume, famously, said he has no experience of a Self, so can't get started on Leibniz's journey. |
| 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) |
| 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) |
| 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. |
| 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) |
| 5027 | If a person's memories became totally those of the King of China, he would be the King of China [Leibniz] |
| Full Idea: If someone were suddenly to become the King of China, forgetting what he has been, as if born anew, is this not as if he were annihilated, and a King of China created in his place at the same moment? | |
| From: Gottfried Leibniz (Discourse on Metaphysics [1686], §34) | |
| A reaction: Strikingly, this clearly endorse the view of the empiricist Locke. It is a view about the continuity of the self, not its essence, but Descartes must have turned in his grave when he read this. When this 'King of China' introspects his self, what is it? |
| 5023 | Future contingent events are certain, because God foresees them, but that doesn't make them necessary [Leibniz] |
| Full Idea: We must distinguish between what is certain and what is necessary; everyone agrees that future contingents are certain, since God foresees them, but it is not thereby admitted that they are necessary. | |
| From: Gottfried Leibniz (Discourse on Metaphysics [1686], §13) | |
| A reaction: An interesting point, since there is presumably a difference between God foreseeing that future squares will have four corners, and His foreseeing the next war. It seems to me, though, that 'certainty' is bad enough news for free will, without necessity. |
| 2119 | People argue for God's free will, but it isn't needed if God acts in perfection following supreme reason [Leibniz] |
| Full Idea: People try to safeguard God's freedom, as though it were not freedom of the highest sort to act in perfection following sovereign reason. | |
| From: Gottfried Leibniz (Discourse on Metaphysics [1686], §03) |
| 5025 | Mind and body can't influence one another, but God wouldn't intervene in the daily routine [Leibniz] |
| Full Idea: It is inconceivable that mind and body should have any influence on one another, and it is unreasonable simply to have recourse to the extraordinary operation of the universal cause in a matter which is ordinary and particular. | |
| From: Gottfried Leibniz (Discourse on Metaphysics [1686], §33) | |
| A reaction: Leibniz was the ultimate intellectual contortionist! Here he is rejecting Cartesian interactionism, and also Malebranche's Occasionalism (God bridges the gap), in order to prepare for his own (daft) theory of what is now called Parallelism. |
| 5026 | Animals lack morality because they lack self-reflection [Leibniz] |
| Full Idea: It is for lack of reflection on themselves that beasts have no moral qualities. | |
| From: Gottfried Leibniz (Discourse on Metaphysics [1686], §34) | |
| A reaction: Interesting, but I think this is false. I would say animals do have a sense of their self, because that is the most basic feature of any mind, but what they lack is second-order thought, that is, ability to reflect on and judge their own beliefs and acts. |
| 22899 | 'Thank goodness that's over' is not like 'thank goodness that happened on Friday' [Prior,AN] |
| Full Idea: One says 'thank goodness that is over', ..and it says something which it is impossible which any use of any tenseless copula with a date should convey. It certainly doesn't mean the same as 'thank goodness that occured on Friday June 15th 1954'. | |
| From: Arthur N. Prior (Changes in Events and Changes in Things [1968]), quoted by Adrian Bardon - Brief History of the Philosophy of Time 4 'Pervasive' | |
| A reaction: [Ref uncertain] This seems to be appealing to ordinary usage, in which tenses have huge significance. If we take time (with its past, present and future) as primitive, then tenses can have full weight. Did tenses mean anything at all to Einstein? |
| 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) |
| 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) |