160 ideas
| 2797 | As coherence expands its interrelations become steadily tighter, culminating only in necessary truth [Dancy,J] |
| 224 | When questions are doubtful we should concentrate not on objects but on ideas of the intellect [Plato] |
| 11283 | There is pure deductive reasoning, and explanatory demonstration reasoning [Aristotle, by Politis] |
| 1672 | Maybe everything could be demonstrated, if demonstration can be reciprocal or circular [Aristotle] |
| 1684 | Two falsehoods can be contrary to one another [Aristotle] |
| 232 | Opposites are as unlike as possible [Plato] |
| 8937 | Plato's 'Parmenides' is the greatest artistic achievement of the ancient dialectic [Hegel on Plato] |
| 12145 | Definitions are of what something is, and that is universal [Aristotle] |
| 12075 | An Aristotelian definition is causal [Aristotle, by Witt] |
| 12384 | Definition by division needs predicates, which are well ordered and thorough [Aristotle] |
| 9066 | You can define objects by progressively identifying what is the same and what is different [Aristotle] |
| 12382 | What it is and why it is are the same; screening defines and explains an eclipse [Aristotle] |
| 2768 | The correspondence theory also has the problem that two sets of propositions might fit the facts equally well [Dancy,J] |
| 2765 | Rescher says that if coherence requires mutual entailment, this leads to massive logical redundancy [Dancy,J] |
| 2769 | If one theory is held to be true, all the other theories appear false, because they can't be added to the true one [Dancy,J] |
| 2766 | Even with a tight account of coherence, there is always the possibility of more than one set of coherent propositions [Dancy,J] |
| 1668 | An axiom is a principle which must be understood if one is to learn anything [Aristotle] |
| 12376 | Demonstrations by reductio assume excluded middle [Aristotle] |
| 12373 | Something holds universally when it is proved of an arbitrary and primitive case [Aristotle] |
| 12363 | Everything is either asserted or denied truly [Aristotle] |
| 13004 | Aristotle's axioms (unlike Euclid's) are assumptions awaiting proof [Aristotle, by Leibniz] |
| 13986 | Plato found antinomies in ideas, Kant in space and time, and Bradley in relations [Plato, by Ryle] |
| 14150 | Plato's 'Parmenides' is perhaps the best collection of antinomies ever made [Russell on Plato] |
| 12377 | Mathematics is concerned with forms, not with superficial properties [Aristotle] |
| 12372 | The essence of a triangle comes from the line, mentioned in any account of triangles [Aristotle] |
| 12369 | A unit is what is quantitatively indivisible [Aristotle] |
| 16150 | One is, so numbers exist, so endless numbers exist, and each one must partake of being [Plato] |
| 229 | The one was and is and will be and was becoming and is becoming and will become [Plato] |
| 21821 | Plato's Parmenides has a three-part theory, of Primal One, a One-Many, and a One-and-Many [Plato, by Plotinus] |
| 2781 | Realism says that most perceived objects exist, and have some of their perceived properties [Dancy,J] |
| 221 | Absolute ideas, such as the Good and the Beautiful, cannot be known by us [Plato] |
| 18910 | To seek truth, study the real connections between subjects and attributes [Aristotle] |
| 223 | If you deny that each thing always stays the same, you destroy the possibility of discussion [Plato] |
| 1675 | Separate Forms aren't needed for logic, but universals (one holding of many) are essential [Aristotle] |
| 227 | You must always mean the same thing when you utter the same name [Plato] |
| 210 | It would be absurd to think there were abstract Forms for vile things like hair, mud and dirt [Plato] |
| 220 | The concept of a master includes the concept of a slave [Plato] |
| 211 | If admirable things have Forms, maybe everything else does as well [Plato] |
| 219 | If absolute ideas existed in us, they would cease to be absolute [Plato] |
| 228 | Greatness and smallness must exist, to be opposed to one another, and come into being in things [Plato] |
| 16151 | Plato moves from Forms to a theory of genera and principles in his later work [Plato, by Frede,M] |
| 215 | If things partake of ideas, this implies either that everything thinks, or that everything actually is thought [Plato] |
| 218 | Participation is not by means of similarity, so we are looking for some other method of participation [Plato] |
| 213 | Each idea is in all its participants at once, just as daytime is a unity but in many separate places at once [Plato] |
| 216 | If things are made alike by participating in something, that thing will be the absolute idea [Plato] |
| 212 | The whole idea of each Form must be found in each thing which participates in it [Plato] |
| 217 | Nothing can be like an absolute idea, because a third idea intervenes to make them alike (leading to a regress) [Plato] |
| 214 | If absolute greatness and great things are seen as the same, another thing appears which makes them seem great [Plato] |
| 1677 | We can forget the Forms, as they are irrelevant, and not needed in giving demonstrations [Aristotle] |
| 1687 | Why are being terrestrial and a biped combined in the definition of man, but being literate and musical aren't? [Aristotle] |
| 15851 | Parts must belong to a created thing with a distinct form [Plato] |
| 1681 | Units are positionless substances, and points are substances with position [Aristotle] |
| 15846 | In Parmenides, if composition is identity, a whole is nothing more than its parts [Plato, by Harte,V] |
| 15849 | Plato says only a one has parts, and a many does not [Plato, by Harte,V] |
| 15850 | Anything which has parts must be one thing, and parts are of a one, not of a many [Plato] |
| 13259 | It seems that the One must be composed of parts, which contradicts its being one [Plato] |
| 12146 | Definitions recognise essences, so are not themselves essences [Aristotle] |
| 17039 | The predicates of a thing's nature are necessary to it [Aristotle] |
| 11994 | Aristotelian essences are properties mentioned at the starting point of a science [Aristotle, by Kung] |
| 15847 | Two things relate either as same or different, or part of a whole, or the whole of the part [Plato] |
| 12381 | What is necessary cannot be otherwise [Aristotle] |
| 1690 | A stone travels upwards by a forced necessity, and downwards by natural necessity [Aristotle] |
| 12072 | For Aristotle knowledge is explanatory, involving understanding, and principles or causes [Aristotle, by Witt] |
| 12073 | 'Episteme' means grasping causes, universal judgments, explanation, and teaching [Aristotle, by Witt] |
| 12378 | The reason why is the key to knowledge [Aristotle] |
| 12364 | We understand a thing when we know its explanation and its necessity [Aristotle] |
| 12366 | We only understand something when we know its explanation [Aristotle] |
| 12370 | Some understanding, of immediate items, is indemonstrable [Aristotle] |
| 1685 | No one has mere belief about something if they think it HAS to be true [Aristotle] |
| 1673 | Knowledge proceeds from principles, so it is hard to know if we know [Aristotle] |
| 2745 | A pupil who lacks confidence may clearly know something but not be certain of it [Dancy,J] |
| 2755 | If senses are fallible, then being open to correction is an epistemological virtue [Dancy,J] |
| 5677 | Naïve direct realists hold that objects retain all of their properties when unperceived [Dancy,J] |
| 5678 | Scientific direct realism says we know some properties of objects directly [Dancy,J] |
| 5681 | Maybe we are forced from direct into indirect realism by the need to explain perceptual error [Dancy,J] |
| 5682 | Internal realism holds that we perceive physical objects via mental objects [Dancy,J] |
| 5683 | Indirect realism depends on introspection, the time-lag, illusions, and neuroscience [Dancy,J, by PG] |
| 2778 | Phenomenalism includes possible experiences, but idealism only refers to actual experiences [Dancy,J] |
| 5684 | Eliminative idealists say there are no objects; reductive idealists say objects exist as complex experiences [Dancy,J] |
| 2777 | Extreme solipsism only concerns current experience, but it might include past and future [Dancy,J] |
| 2794 | Knowing that a cow is not a horse seems to be a synthetic a priori truth [Dancy,J] |
| 12379 | You cannot understand anything through perception [Aristotle] |
| 2780 | Perception is either direct realism, indirect realism, or phenomenalism [Dancy,J] |
| 16725 | Some knowledge is lost if you lose a sense, and there is no way the knowledge can be replaced [Aristotle] |
| 5680 | For direct realists the secondary and primary qualities seem equally direct [Dancy,J] |
| 5679 | We can't grasp the separation of quality types, or what a primary-quality world would be like [Dancy,J] |
| 2782 | We can be looking at distant stars which no longer actually exist [Dancy,J] |
| 2775 | It is not clear from the nature of sense data whether we should accept them as facts [Dancy,J] |
| 2784 | Appearances don't guarantee reality, unless the appearance is actually caused by the reality [Dancy,J] |
| 2785 | Perceptual beliefs may be directly caused, but generalisations can't be [Dancy,J] |
| 23309 | Aristotle's concepts of understanding and explanation mean he is not a pure empiricist [Aristotle, by Frede,M] |
| 1693 | Animals may have some knowledge if they retain perception, but understanding requires reasons to be given [Aristotle] |
| 9067 | Many memories of the same item form a single experience [Aristotle] |
| 2788 | If perception and memory are indirect, then two things stand between mind and reality [Dancy,J] |
| 2787 | Memories aren't directly about the past, because time-lags and illusions suggest representation [Dancy,J] |
| 2791 | Phenomenalism about memory denies the past, or reduces it to present experience [Dancy,J] |
| 2790 | I can remember plans about the future, and images aren't essential (2+3=5) [Dancy,J] |
| 1671 | Sceptics say justification is an infinite regress, or it stops at the unknowable [Aristotle] |
| 2754 | Foundations are justified by non-beliefs, or circularly, or they need no justification [Dancy,J] |
| 2749 | For internalists we must actually know that the fact caused the belief [Dancy,J] |
| 2770 | Internalists tend to favour coherent justification, but not the coherence theory of truth [Dancy,J] |
| 2752 | Foundationalism requires inferential and non-inferential justification [Dancy,J] |
| 2771 | Foundationalists must accept not only the basic beliefs, but also rules of inference for further progress [Dancy,J] |
| 1670 | When you understand basics, you can't be persuaded to change your mind [Aristotle] |
| 2756 | If basic beliefs can be false, falsehood in non-basic beliefs might by a symptom [Dancy,J] |
| 2753 | Beliefs can only be infallible by having almost no content [Dancy,J] |
| 2773 | Coherentism gives a possible justification of induction, and opposes scepticism [Dancy,J] |
| 2779 | Idealists must be coherentists, but coherentists needn't be idealists [Dancy,J] |
| 2786 | For coherentists justification and truth are not radically different things [Dancy,J] |
| 2767 | If it is empirical propositions which have to be coherent, this eliminates coherent fiction [Dancy,J] |
| 2776 | Externalism could even make belief unnecessary (e.g. in animals) [Dancy,J] |
| 2746 | How can a causal theory of justification show that all men die? [Dancy,J] |
| 2747 | Causal theories don't allow for errors in justification [Dancy,J] |
| 2772 | Coherentism moves us towards a more social, shared view of knowledge [Dancy,J] |
| 2743 | What is the point of arguing against knowledge, if being right undermines your own argument? [Dancy,J] |
| 12371 | A demonstration is a deduction which proceeds from necessities [Aristotle] |
| 12147 | The principles of demonstrations are definitions [Aristotle] |
| 1691 | Aim to get definitions of the primitive components, thus establishing the kind, and work towards the attributes [Aristotle] |
| 12383 | There must be definitions before demonstration is possible [Aristotle] |
| 1674 | All demonstration is concerned with existence, axioms and properties [Aristotle] |
| 24068 | Demonstration is more than entailment, as the explanatory order must match the causal order [Aristotle, by Koslicki] |
| 17310 | Aristotle gets asymmetric consequence from demonstration, which reflects real causal priority [Aristotle, by Koslicki] |
| 21359 | Aristotle doesn't actually apply his theory of demonstration to his practical science [Leroi on Aristotle] |
| 1667 | Premises must be true, primitive and immediate, and prior to and explanatory of conclusions [Aristotle] |
| 12365 | We can know by demonstration, which is a scientific deduction leading to understanding [Aristotle] |
| 10918 | Demonstrative understanding rests on necessary features of the thing in itself [Aristotle] |
| 12374 | Demonstrations must be necessary, and that depends on the middle term [Aristotle] |
| 12148 | Demonstrations are syllogisms which give explanations [Aristotle] |
| 1679 | Universal demonstrations are about thought; particular demonstrations lead to perceptions [Aristotle] |
| 1680 | Demonstration is better with fewer presuppositions, and it is quicker if these are familiar [Aristotle] |
| 1683 | We learn universals from many particulars [Aristotle] |
| 2751 | Probabilities can only be assessed relative to some evidence [Dancy,J] |
| 12385 | Are particulars explained more by universals, or by other particulars? [Aristotle] |
| 12367 | What is most universal is furthest away, and the particulars are nearest [Aristotle] |
| 12380 | Universals are valuable because they make the explanations plain [Aristotle] |
| 1689 | Explanation is of the status of a thing, inferences to it, initiation of change, and purpose [Aristotle] |
| 1686 | What we seek and understand are facts, reasons, existence, and identity [Aristotle] |
| 12357 | Explanation and generality are inseparable [Aristotle, by Wedin] |
| 1669 | The foundation or source is stronger than the thing it causes [Aristotle] |
| 1678 | Universals give better explanations, because they are self-explanatory and primitive [Aristotle] |
| 2757 | The argument from analogy rests on one instance alone [Dancy,J] |
| 2758 | You can't separate mind and behaviour, as the analogy argument attempts [Dancy,J] |
| 9068 | Perception creates primitive immediate principles by building a series of firm concepts [Aristotle] |
| 9069 | A perception lodging in the soul creates a primitive universal, which becomes generalised [Aristotle] |
| 9070 | We learn primitives and universals by induction from perceptions [Aristotle] |
| 2744 | Verificationism (the 'verification principle') is an earlier form of anti-realism [Dancy,J] |
| 2760 | Logical positivism implies foundationalism, by dividing weak from strong verifications [Dancy,J] |
| 2761 | If the meanings of sentences depend on other sentences, how did we learn language? [Dancy,J] |
| 12368 | Negation takes something away from something [Aristotle] |
| 2763 | There is an indeterminacy in juggling apparent meanings against probable beliefs [Dancy,J] |
| 2762 | Charity makes native beliefs largely true, and Humanity makes them similar to ours [Dancy,J] |
| 1692 | If you shouldn't argue in metaphors, then you shouldn't try to define them either [Aristotle] |
| 222 | Only a great person can understand the essence of things, and an even greater person can teach it [Plato] |
| 225 | The unlimited has no shape and is endless [Plato] |
| 233 | Some things do not partake of the One [Plato] |
| 2062 | The only movement possible for the One is in space or in alteration [Plato] |
| 231 | Everything partakes of the One in some way [Plato] |
| 12375 | Whatever holds of a kind intrinsically holds of it necessarily [Aristotle] |
| 234 | We couldn't discuss the non-existence of the One without knowledge of it [Plato] |
| 1688 | Properties must be proved, but not essence; but existents are not a kind, so existence isn't part of essence [Aristotle] |