102 ideas
| 21267 | Supposing many principles is superfluous if a few will do it [Aquinas] |
| 23176 | Truth is universal, but knowledge of it is not [Aquinas] |
| 20621 | Types of lying: Speak lies, intend lies, intend deception, aim at deceptive goal? [Aquinas, by Tuckness/Wolf] |
| 21248 | If the existence of truth is denied, the 'Truth does not exist' must be true! [Aquinas] |
| 18395 | Sets are mereological sums of the singletons of their members [Lewis, by Armstrong] |
| 15496 | We can build set theory on singletons: classes are then fusions of subclasses, membership is the singleton [Lewis] |
| 15500 | Classes divide into subclasses in many ways, but into members in only one way [Lewis] |
| 15499 | A subclass of a subclass is itself a subclass; a member of a member is not in general a member [Lewis] |
| 15503 | We needn't accept this speck of nothingness, this black hole in the fabric of Reality! [Lewis] |
| 15498 | We can accept the null set, but there is no null class of anything [Lewis] |
| 15502 | There are four main reasons for asserting that there is an empty set [Lewis] |
| 15506 | If we don't understand the singleton, then we don't understand classes [Lewis] |
| 15497 | We can replace the membership relation with the member-singleton relation (plus mereology) [Lewis] |
| 15511 | If singleton membership is external, why is an object a member of one rather than another? [Lewis] |
| 15513 | Maybe singletons have a structure, of a thing and a lasso? [Lewis] |
| 15507 | Set theory has some unofficial axioms, generalisations about how to understand it [Lewis] |
| 10191 | Set theory reduces to a mereological theory with singletons as the only atoms [Lewis, by MacBride] |
| 15508 | If singletons are where their members are, then so are all sets [Lewis] |
| 15514 | A huge part of Reality is only accepted as existing if you have accepted set theory [Lewis] |
| 15523 | Set theory isn't innocent; it generates infinities from a single thing; but mathematics needs it [Lewis] |
| 23173 | If a syllogism admits one absurdity, others must follow [Aquinas] |
| 15525 | Plural quantification lacks a complete axiom system [Lewis] |
| 15518 | I like plural quantification, but am not convinced of its connection with second-order logic [Lewis] |
| 15524 | Zermelo's model of arithmetic is distinctive because it rests on a primitive of set theory [Lewis] |
| 15517 | Giving up classes means giving up successful mathematics because of dubious philosophy [Lewis] |
| 15515 | To be a structuralist, you quantify over relations [Lewis] |
| 15520 | Existence doesn't come in degrees; once asserted, it can't then be qualified [Lewis] |
| 15812 | Being implies distinctness, which implies division, unity, and multitude [Aquinas] |
| 15501 | We have no idea of a third sort of thing, that isn't an individual, a class, or their mixture [Lewis] |
| 15504 | Atomless gunk is an individual whose parts all have further proper parts [Lewis] |
| 21268 | Non-human things are explicable naturally, and voluntary things by the will, so God is not needed [Aquinas] |
| 15516 | A property is any class of possibilia [Lewis] |
| 16765 | Humans only have a single substantial form, which contains the others and acts for them [Aquinas] |
| 14748 | The many are many and the one is one, so they can't be identical [Lewis] |
| 6129 | Lewis affirms 'composition as identity' - that an object is no more than its parts [Lewis, by Merricks] |
| 15512 | In mereology no two things consist of the same atoms [Lewis] |
| 15519 | Trout-turkeys exist, despite lacking cohesion, natural joints and united causal power [Lewis] |
| 15521 | Given cats, a fusion of cats adds nothing further to reality [Lewis] |
| 15522 | The one has different truths from the many; it is one rather than many, one rather than six [Lewis] |
| 14244 | Lewis only uses fusions to create unities, but fusions notoriously flatten our distinctions [Oliver/Smiley on Lewis] |
| 10660 | A commitment to cat-fusions is not a further commitment; it is them and they are it [Lewis] |
| 10566 | Lewis prefers giving up singletons to giving up sums [Lewis, by Fine,K] |
| 14221 | Serious essentialism says everything has essences, they're not things, and they ground necessities [Shalkowski] |
| 14222 | Essences are what it is to be that (kind of) thing - in fact, they are the thing's identity [Shalkowski] |
| 14226 | We distinguish objects by their attributes, not by their essences [Shalkowski] |
| 14225 | Critics say that essences are too mysterious to be known [Shalkowski] |
| 14223 | De dicto necessity has linguistic entities as their source, so it is a type of de re necessity [Shalkowski] |
| 23175 | The conclusions of speculative reason about necessities are certain [Aquinas] |
| 21337 | A knowing being possesses a further reality, the 'presence' of the thing known [Aquinas] |
| 21249 | Some things are self-evident to us; others are only self-evident in themselves [Aquinas] |
| 21250 | A proposition is self-evident if the predicate is included in the essence of the subject [Aquinas] |
| 15509 | Some say qualities are parts of things - as repeatable universals, or as particulars [Lewis] |
| 20224 | Sensation prepares the way for intellectual knowledge, which needs the virtues of reason [Aquinas] |
| 22107 | Sensations are transmitted to 'internal senses' in the brain, chiefly to 'phantasia' and 'imagination' [Aquinas, by Kretzmann/Stump] |
| 9098 | Mental activity combines what we sense with imagination of what is not present [Aquinas] |
| 9092 | Abstracting A from B generates truth, as long as the connection is not denied [Aquinas] |
| 9093 | We understand the general nature of things by ignoring individual peculiarities [Aquinas] |
| 9097 | The mind abstracts generalities from images, but also uses images for understanding [Aquinas] |
| 9095 | Very general ideas (being, oneness, potentiality) can be abstracted from thought matter in general [Aquinas] |
| 9099 | Particular instances come first, and (pace Plato) generalisations are abstracted from them [Aquinas] |
| 10508 | Species are abstracted from appearances by ignoring individual conditions [Aquinas] |
| 22111 | Aquinas attributes freedom to decisions and judgements, and not to the will alone [Aquinas, by Kretzmann/Stump] |
| 22105 | The human intellectual soul is an incorporeal, subsistent principle [Aquinas] |
| 22108 | First grasp what it is, then its essential features; judgement is their compounding and division [Aquinas] |
| 10503 | We abstract forms from appearances, and acquire knowledge of immaterial things [Aquinas] |
| 10509 | Understanding consists entirely of grasping abstracted species [Aquinas] |
| 10506 | Mathematics can be abstracted from sensible matter, and from individual intelligible matter [Aquinas] |
| 9094 | Mathematical objects abstract both from perceived matter, and from particular substance [Aquinas] |
| 10505 | We can just think of an apple's colour, because the apple is not part of the colour's nature [Aquinas] |
| 10504 | Abstracting either treats something as separate, or thinks of it separately [Aquinas] |
| 10507 | Numbers and shapes are abstracted by ignoring their sensible qualities [Aquinas] |
| 9096 | The mind must produce by its own power an image of the individual species [Aquinas] |
| 14224 | Equilateral and equiangular aren't the same, as we have to prove their connection [Shalkowski] |
| 23180 | The will is the rational appetite [Aquinas] |
| 22112 | For humans good is accordance with reason, and bad is contrary to reason [Aquinas] |
| 22494 | We must know the end, know that it is the end, and know how to attain it [Aquinas] |
| 23181 | All acts of virtue relate to justice, which is directed towards the common good [Aquinas] |
| 8009 | Aquinas wanted, not to escape desire, but to transform it for moral ends [Aquinas, by MacIntyre] |
| 23182 | Legal justice is supreme, because it directs the other virtues to the common good [Aquinas] |
| 22399 | Temperance prevents our passions from acting against reason [Aquinas] |
| 23177 | Justice directs our relations with others, because it denotes a kind of equality [Aquinas] |
| 23179 | People differ in their social degrees, and a particular type of right applies to each [Aquinas] |
| 23174 | Natural law is a rational creature's participation in eternal law [Aquinas] |
| 22114 | Tyrannical laws are irrational, and so not really laws [Aquinas] |
| 22113 | Right and wrong actions pertain to natural law, as perceived by practical reason [Aquinas] |
| 7291 | For Aquinas a war must be in a just cause, have proper authority, and aim at good [Aquinas, by Grayling] |
| 5508 | Aquinas says a fertilized egg is not human, and has no immortal soul [Aquinas, by Martin/Barresi] |
| 16687 | Bodies are three-dimensional substances [Aquinas] |
| 23178 | Divine law commands some things because they are good, while others are good because commanded [Aquinas] |
| 21251 | We can't know God's essence, so his existence can't be self-evident for us [Aquinas] |
| 5614 | If you assume that there must be a necessary being, you can't say which being has this quality [Kant on Aquinas] |
| 21269 | Way 1: the infinite chain of potential-to-actual movement has to have a first mover [Aquinas] |
| 21270 | Way 2: no effect without a cause, and this cannot go back to infinity, so there is First Cause [Aquinas] |
| 21271 | Way 3: contingent beings eventually vanish, so continuity needs a necessary being [Aquinas] |
| 21272 | Way 4: the source of all qualities is their maximum, so something (God) causes all perfections [Aquinas] |
| 21273 | Way 5: mindless things act towards an obvious end, so there is an intelligent director [Aquinas] |
| 20211 | Life aims at the Beatific Vision - of perfect happiness, and revealed truth [Aquinas, by Zagzebski] |
| 22106 | Aquinas saw angels as separated forms, rather than as made of 'spiritual matter' [Aquinas, by Kretzmann/Stump] |
| 23306 | Humans have a non-physical faculty of reason, so they can be immortal [Aquinas, by Sorabji] |
| 4412 | Those in bliss have their happiness increased by seeing the damned punished [Aquinas] |
| 21266 | God does not exist, because He is infinite and good, and so no evil should be discoverable [Aquinas] |
| 21274 | It is part of God's supreme goodness that He brings good even out of evil [Aquinas] |