85 ideas
| 21267 | Supposing many principles is superfluous if a few will do it [Aquinas] |
| Full Idea: It is superfluous to suppose that what can be accounted for by a few principles has been produced by many. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia,Q02,Art3,Ob2) | |
| A reaction: Notice that this is 'superfluous' rather than 'wrong'. But ten people can lift a piano which could have been lifted by eight. Note that this is 150 years before Ockham. |
| 23176 | Truth is universal, but knowledge of it is not [Aquinas] |
| Full Idea: The truth is the same for all, but is not equally known to all. | |
| From: Thomas Aquinas (Summa Theologicae [1265], I-II Q94 4) | |
| A reaction: Amazing how many modern thinkers fail to grasp this simple distinction. However, the truth is not quite the same for all if diverse persons are expressing a single truth with different concepts and languages. The word 'facts' is helpful here. |
| 20621 | Types of lying: Speak lies, intend lies, intend deception, aim at deceptive goal? [Aquinas, by Tuckness/Wolf] |
| Full Idea: Lying can involve (1) speaking false words, (2) the intention to speak false words, (3) the intention of bringing about deception, and (4) the ultimate goal of one's deception. | |
| From: report of Thomas Aquinas (Summa Theologicae [1265], Q110) by Tuckness,A/Wolf,C - This is Political Philosophy 10 'Lying' | |
| A reaction: It's a start, but much more is needed to clarify lying. Irony is an obvious problem with (1). |
| 13252 | Some truths have true negations [Beall/Restall] |
| Full Idea: Dialetheism is the view that some truths have true negations. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 7.4) | |
| A reaction: The important thing to remember is that they are truths. Thus 'Are you feeling happy?' might be answered 'Yes and no'. |
| 21248 | If the existence of truth is denied, the 'Truth does not exist' must be true! [Aquinas] |
| Full Idea: Whoever denies the existence of truth grants that truth does not exist: and if truth does not exist, then the proposition 'Truth does not exist' is true: and if there is anything true, there must be truth. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Art 1, Obj 3) | |
| A reaction: A classic example of turning the tables, also applicable to anyone who firmly denies knowledge, or that words are meaningful, or says that meaning needs verification. However, one measily truth is not much consolation. |
| 13247 | A truthmaker is an object which entails a sentence [Beall/Restall] |
| Full Idea: The truthmaker thesis is that an object is a truthmaker for a sentence if and only if its existence entails the sentence. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.5.3) | |
| A reaction: The use of the word 'object' here is even odder than usual, and invites many questions. And the 'only if' seems peculiar, since all sorts of things can make a sentence true. 'There is someone in the house' for example. |
| 13249 | (∀x)(A v B) |- (∀x)A v (∃x)B) is valid in classical logic but invalid intuitionistically [Beall/Restall] |
| Full Idea: The inference of 'distribution' (∀x)(A v B) |- (∀x)A v (∃x)B) is valid in classical logic but invalid intuitionistically. It is straightforward to construct a 'stage' at which the LHS is true but the RHS is not. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 6.1.2) | |
| A reaction: This seems to parallel the iterative notion in set theory, that you must construct your hierarchy. All part of the general 'constructivist' approach to things. Is some kind of mad platonism the only alternative? |
| 13243 | Excluded middle must be true for some situation, not for all situations [Beall/Restall] |
| Full Idea: Relevant logic endorses excluded middle, ..but says instances of the law may fail. Bv¬B is true in every situation that settles the matter of B. It is necessary that there is some such situation. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.2) | |
| A reaction: See next idea for the unusual view of necessity on which this rests. It seems easier to assert something about all situations than just about 'some' situation. |
| 13242 | It's 'relevantly' valid if all those situations make it true [Beall/Restall] |
| Full Idea: The argument from P to A is 'relevantly' valid if and only if, for every situation in which each premise in P is true, so is A. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.2) | |
| A reaction: I like the idea that proper inference should have an element of relevance to it. A falsehood may allow all sorts of things, without actually implying them. 'Situations' sound promising here. |
| 13246 | Relevant logic does not abandon classical logic [Beall/Restall] |
| Full Idea: We have not abandoned classical logic in our acceptance of relevant logic. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.4) | |
| A reaction: It appears that classical logic is straightforwardly accepted, but there is a difference of opinion over when it is applicable. |
| 13245 | Relevant consequence says invalidity is the conclusion not being 'in' the premises [Beall/Restall] |
| Full Idea: Relevant consequence says the conclusion of a relevantly invalid argument is not 'carried in' the premises - it does not follow from the premises. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.3.3) | |
| A reaction: I find this appealing. It need not invalidate classical logic. It is just a tougher criterion which is introduced when you want to do 'proper' reasoning, instead of just playing games with formal systems. |
| 13254 | A doesn't imply A - that would be circular [Beall/Restall] |
| Full Idea: We could reject the inference from A to itself (on grounds of circularity). | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 8) | |
| A reaction: [Martin-Meyer System] 'It's raining today'. 'Are you implying that it is raining today?' 'No, I'm SAYING it's raining today'. Logicians don't seem to understand the word 'implication'. Logic should capture how we reason. Nice proposal. |
| 13255 | Relevant logic may reject transitivity [Beall/Restall] |
| Full Idea: Some relevant logics reject transitivity, but we defend the classical view. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 8) | |
| A reaction: [they cite Neil Tennant for this view] To reject transitivity (A?B ? B?C ? A?C) certainly seems a long way from classical logic. But in everyday inference Tennant's idea seems good. The first premise may be irrelevant to the final conclusion. |
| 13250 | Free logic terms aren't existential; classical is non-empty, with referring names [Beall/Restall] |
| Full Idea: A logic is 'free' to the degree it refrains from existential import of its singular and general terms. Classical logic must have non-empty domain, and each name must denote in the domain. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 7.1) | |
| A reaction: My intuition is that logic should have no ontology at all, so I like the sound of 'free' logic. We can't say 'Pegasus does not exist', and then reason about Pegasus just like any other horse. |
| 13235 | Logic studies consequence; logical truths are consequences of everything, or nothing [Beall/Restall] |
| Full Idea: Nowadays we think of the consequence relation itself as the primary subject of logic, and view logical truths as degenerate instances of this relation. Logical truths follow from any set of assumptions, or from no assumptions at all. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.2) | |
| A reaction: This seems exactly right; the alternative is the study of necessities, but that may not involve logic. |
| 13238 | Syllogisms are only logic when they use variables, and not concrete terms [Beall/Restall] |
| Full Idea: According to the Peripatetics (Aristotelians), only syllogistic laws stated in variables belong to logic, and not their applications to concrete terms. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.5) | |
| A reaction: [from Lukasiewicz] Seems wrong. I take it there are logical relations between concrete things, and the variables are merely used to describe these relations. Variables lack the internal powers to drive logical necessities. Variables lack essence! |
| 13234 | The view of logic as knowing a body of truths looks out-of-date [Beall/Restall] |
| Full Idea: Through much of the 20th century the conception of logic was inherited from Frege and Russell, as knowledge of a body of logical truths, as arithmetic or geometry was a knowledge of truths. This is odd, and a historical anomaly. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.2) | |
| A reaction: Interesting. I have always taken this idea to be false. I presume logic has minimal subject matter and truths, and preferably none at all. |
| 13232 | Logic studies arguments, not formal languages; this involves interpretations [Beall/Restall] |
| Full Idea: Logic does not study formal languages for their own sake, which is formal grammar. Logic evaluates arguments, and primarily considers formal languages as interpreted. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.1) | |
| A reaction: Hodges seems to think logic just studies formal languages. The current idea strikes me as a much more sensible view. |
| 13241 | The model theory of classical predicate logic is mathematics [Beall/Restall] |
| Full Idea: The model theory of classical predicate logic is mathematics if anything is. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 4.2.1) | |
| A reaction: This is an interesting contrast to the claim of logicism, that mathematics reduces to logic. This idea explains why students of logic are surprised to find themselves involved in mathematics. |
| 23173 | If a syllogism admits one absurdity, others must follow [Aquinas] |
| Full Idea: In syllogistic arguments, granted one absurdity, others must follow too. | |
| From: Thomas Aquinas (Summa Theologicae [1265], I-II Q19 6) | |
| A reaction: This asserts the necessity of logical consequence, which he derives from Aristotle. |
| 13253 | There are several different consequence relations [Beall/Restall] |
| Full Idea: We are pluralists about logical consequence because we take there to be a number of different consequence relations, each reflecting different precisifications of the pre-theoretic notion of deductive logical consequence. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 8) | |
| A reaction: I don't see how you avoid the slippery slope that leads to daft logical rules like Prior's 'tonk' (from which you can infer anything you like). I say that nature imposes logical conquence on us - but don't ask me to prove it. |
| 13240 | A sentence follows from others if they always model it [Beall/Restall] |
| Full Idea: The sentence X follows logically from the sentences of the class K if and only if every model of the class K is also a model of the sentence X. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 3.2) | |
| A reaction: This why the symbol |= is often referred to as 'models'. |
| 13236 | Logical truth is much more important if mathematics rests on it, as logicism claims [Beall/Restall] |
| Full Idea: If mathematical truth reduces to logical truth then it is important what counts as logically true, …but if logicism is not a going concern, then the body of purely logical truths will be less interesting. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.2) | |
| A reaction: Logicism would only be one motivation for pursuing logical truths. Maybe my new 'Necessitism' will derive the Peano Axioms from broad necessary truths, rather than from logic. |
| 13237 | Preface Paradox affirms and denies the conjunction of propositions in the book [Beall/Restall] |
| Full Idea: The Paradox of the Preface is an apology, that you are committed to each proposition in the book, but admit that collectively they probably contain a mistake. There is a contradiction, of affirming and denying the conjunction of propositions. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.4) | |
| A reaction: This seems similar to the Lottery Paradox - its inverse perhaps. Affirm all and then deny one, or deny all and then affirm one? |
| 15812 | Being implies distinctness, which implies division, unity, and multitude [Aquinas] |
| Full Idea: What first comes to mind is being; secondly, that this being is not that being, and thus we apprehend division as a consequence; thirdly, comes the notion of one; fourthly the notion of multitude. | |
| From: Thomas Aquinas (Summa Theologicae [1265], I Q11 ar2 ad4), quoted by Roderick Chisholm - Person and Object 1.5 | |
| A reaction: This is one of the best things I have read on 'being'. It is the Aristotelian recognition that we can only study being by studying identity, and that this leads on to wider metaphysics. Other approaches to being are dead ends. |
| 21268 | Non-human things are explicable naturally, and voluntary things by the will, so God is not needed [Aquinas] |
| Full Idea: All natural things can be reduced to one principle, which is nature; and all voluntary things can be reduced to one principle, which is human reason, or will. Therefore God does not exist. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia,Q02,Art3,Ob2) | |
| A reaction: Not, of course, the opinion of Aquinas. So the possibility of naturalism (assuming the human will can be further reduced to nature) was a clear option in the thirteenth century. In reply Aquinas cites his Fifth Way. |
| 16765 | Humans only have a single substantial form, which contains the others and acts for them [Aquinas] |
| Full Idea: A human being has no substantial form other than the intellective soul alone, and it contains the sensitive and nutritive souls, and all lower forms, and it alone brings about whatever it is that less perfect forms bring about in other things. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia Q76 4c), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 25.1 | |
| A reaction: He says brutes and plants also have a single soul. Pasnau says this is Aquinas's most distinctive doctrine, because other thinkers postulate a whole hierarchy of substantial forms. |
| 13244 | Relevant necessity is always true for some situation (not all situations) [Beall/Restall] |
| Full Idea: In relevant logic, the necessary truths are not those which are true in every situation; rather, they are those for which it is necessary that there is a situation making them true. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.2) | |
| A reaction: This seems to rest on the truthmaker view of such things, which I find quite attractive (despite Merricks's assault). Always ask what is making some truth necessary. This leads you to essences. |
| 23175 | The conclusions of speculative reason about necessities are certain [Aquinas] |
| Full Idea: Since the speculative reason is concerned chiefly with necessary things, which cannot be otherwise than they are, its proper conclusions, like the universal principles, contain the truth without fail. | |
| From: Thomas Aquinas (Summa Theologicae [1265], I-II Q94 4) | |
| A reaction: This seems over-confident, and to confuse the facts with our knowledge of the facts. Simple arithmetic may seem certain, but long and intricate proofs are always a little uncertain. |
| 21337 | A knowing being possesses a further reality, the 'presence' of the thing known [Aquinas] |
| Full Idea: Knowing beings are differentiated from non-knowing beings by this: non-knowing beings have only their own reality, but knowing beings are capable of possessing also the reality of something else, ...a presence of the thing known produced by this thing. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia,q.Q14,art 1) | |
| A reaction: [Quoted by Ryan Meade in a talk at Pigotts] A famous and much discussed remark. Aquinas was a direct realist about perception, so this presence seems to be the thing itself, rather than a 'representation'. |
| 21249 | Some things are self-evident to us; others are only self-evident in themselves [Aquinas] |
| Full Idea: A thing can be self-evident in either of two ways: on the one hand, self-evident in itself, though not to us; on the other hand, self-evident in itself, and to us. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Art 1, Obj 3) | |
| A reaction: A clear distinction, which is hard to deny, though there are lots of borderline cases. Self-evident to genius, and self-evident to future genius. Self-evident to almost everyone. Goldbach's Conjecture may be self-evident but unknowable. |
| 21250 | A proposition is self-evident if the predicate is included in the essence of the subject [Aquinas] |
| Full Idea: A proposition is self-evident because the predicate is included in the essence of the subject. E.g. Man is an animal, because animal is included in the essence of man. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Art 1, Obj 3) | |
| A reaction: Aquinas focuses on the essence of the subject, where Kant embraces the whole concept of the subject. Is it self-evident that we are genetically related to apes? Yes, to a geneticiist. Is that part of human essence? No. So Kant wins. |
| 20224 | Sensation prepares the way for intellectual knowledge, which needs the virtues of reason [Aquinas] |
| Full Idea: Knowledge of truth is not consummated in the sensitive powers of apprehension, for these prepare the way to intellectual knowledge. And therefore in these powers there are none of the virtues by which we know truth; these are in the intellect or reason. | |
| From: Thomas Aquinas (Summa Theologicae [1265], I-II Q56 a5 obj3), quoted by Linda Trinkaus Zagzebski - Virtues of the Mind III 2.2 | |
| A reaction: A gem of a quotation for Zagzebski's thesis, that knowledge is defined in terms of the intellectual virtues. The only virtues of perception are in focusing and paying attention to features. Good eyesight is a biological 'virtue', I suppose. |
| 22107 | Sensations are transmitted to 'internal senses' in the brain, chiefly to 'phantasia' and 'imagination' [Aquinas, by Kretzmann/Stump] |
| Full Idea: Sensory species received in external senses are transmitted to 'internal senses', organs located in the brain. The most important of these for cognition are 'phantasia' and 'imagination' (part of phantasia), which produce and preserve 'phantasms'. | |
| From: report of Thomas Aquinas (Summa Theologicae [1265]) by Kretzmann/Stump - Aquinas, Thomas 11 | |
| A reaction: This seems to make Aquinas a representative realist. I add this to my portfolio of philosophical faculties - those required by philosophy, rather than by psychology or neuroscience. |
| 9098 | Mental activity combines what we sense with imagination of what is not present [Aquinas] |
| Full Idea: Mental activity combines two activities which in the senses are distinct: exterior perception in which we are simply affected by what we sense, and interior imagination in which we create images of things that are not, and never have been present. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ch.5 Q85.2) | |
| A reaction: Geach cites this thought to show that he is anti-abstractionist, since mind creates images, and these can arise from things which have not been experienced. Any defence of abstractionism must allow an active power to imagination. |
| 9092 | Abstracting A from B generates truth, as long as the connection is not denied [Aquinas] |
| Full Idea: Abstacting A from B can mean denying A's connection with B, or simply thinking A without thinking B. Abstracting what in reality is connected generates falsehood if done the first way, but not if done the second. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ch.5 Q85.1) | |
| A reaction: Despite Geach's denials, this seems to make Aquinas a classic abstractionist. He goes on to distinguish two sorts of abstraction, but he certainly thinks of abstraction from sense experience as a revelation about the nature of reality. |
| 9093 | We understand the general nature of things by ignoring individual peculiarities [Aquinas] |
| Full Idea: If we think what defines a stone, man or horse, without thinking of any individual peculiarities it may have, this is precisely what we do when we abstract the general nature of what we understand from any particular way in which we imagine it. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ch.5 Q85.1) | |
| A reaction: This may not be simple abstraction from sense experience, since there would obviously be a threatened circularity in the process. Do you need to know the essential definition first, in order to discard the individual peculiarities? |
| 9097 | The mind abstracts generalities from images, but also uses images for understanding [Aquinas] |
| Full Idea: Our mind both abstracts the species from images when it attends to the general nature of things, and understand the species in the images when it has recourse to the images in order to understand the things whose species it has abstracted. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ch.5 Q85.1) | |
| A reaction: Geach claims that the second half of this idea means that Aquinas is not an abstractionist, but he seems to be explictly abstractionist about the way in which we create higher level concepts from lower ones. |
| 9095 | Very general ideas (being, oneness, potentiality) can be abstracted from thought matter in general [Aquinas] |
| Full Idea: There are even things we can abstract from thought matter in general, things like being and oneness and potentiality and realization. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ch.5 Q85.1) | |
| A reaction: The Aristotelian 'potentiality' means possibility, which means that modality is understood by abstraction. Aquinas seems to have four levels: particular perceived, general perceived, particular thought, and general thought. This is the highest level. |
| 9099 | Particular instances come first, and (pace Plato) generalisations are abstracted from them [Aquinas] |
| Full Idea: The generality attaching to a nature - its relatedness to many particular instances - results from abstraction, so in this sense a generalized nature presupposes its instances, and does not, as Plato thought, precede them. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ch.5 Q85.2) | |
| A reaction: This seems to be a quite explicit endorsement of abstractionism by Aquinas, despite all Geach's assertions to the contrary. |
| 10508 | Species are abstracted from appearances by ignoring individual conditions [Aquinas] |
| Full Idea: The agent intellect abstracts intelligible species from phantasms insofar as through the power of the agent intellect we can take into our consideration the natures of the species without the individual conditions. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Q85 Ad4) | |
| A reaction: There might be a threatened circularity here, in trying to decide which features to ignore and which to retain. If we saw a hundred horses with a white nose blaze, we still wouldn't be sure that this was essential to a horse. Innate notions of species?? |
| 22111 | Aquinas attributes freedom to decisions and judgements, and not to the will alone [Aquinas, by Kretzmann/Stump] |
| Full Idea: Aquinas conceives of freedom as free decision or judgement, which cannot be attributed to the will alone. | |
| From: report of Thomas Aquinas (Summa Theologicae [1265]) by Kretzmann/Stump - Aquinas, Thomas 12 | |
| A reaction: This idea might improve the free will debate considerably, because it is not clear what sort of thing a 'will' is, and it is not clear how an entity can be 'free' in isolation, by its intrinsic nature. Isn't all freedom contextual? |
| 22105 | The human intellectual soul is an incorporeal, subsistent principle [Aquinas] |
| Full Idea: It is necessary to say that that which is the principle of intellective activity, what we call the soul of a human being, is an incorporeal, subsistent principle. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia.Q75 2c), quoted by Kretzmann/Stump - Aquinas, Thomas 10 | |
| A reaction: Note 'subsistent' rather than 'existent' (capable of independence?). This identifies the immortal soul with the conscious mind. 'Principle' is an odd word, presumably with roots in Aristotle. It seems to be an Aristotelian 'form' [morphe]. |
| 22108 | First grasp what it is, then its essential features; judgement is their compounding and division [Aquinas] |
| Full Idea: The intellect first apprehends the quiddity of a thing. ...Then it acquires the properties, accidents and dispositions associated with the thing's essence. It must proceed from one compounding or dividing of aspects to another, which is reasoning. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia.Q85 5c), quoted by Kretzmann/Stump - Aquinas, Thomas 11 | |
| A reaction: [compressed] Tracking the process of acquiring knowledge of a thing (rather than necessary and sufficient conditions for full knowledge) is closer to Quine's naturalised epistemology than to the standard analytic approach to the concept of knowledge. |
| 13239 | Judgement is always predicating a property of a subject [Beall/Restall] |
| Full Idea: All judgement, for Kant, is essentially the predication of some property to some subject. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.5) | |
| A reaction: Presumably the denial of a predicate could be a judgement, or the affirmation of ambiguous predicates? |
| 10503 | We abstract forms from appearances, and acquire knowledge of immaterial things [Aquinas] |
| Full Idea: To cognize that which is in individual matter, not as it is in such matter, is to abstract the form from the individual matter that the phantasms represents. Thus we come to a degree of cognition of immaterial things. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Q85 1 Reply) | |
| A reaction: This offers abstraction as a kind of inference to best explanation which takes us beyond immediate empirical experience to what is behind it. Aquinas thinks the concepts and explanation are spiritual, but they may be generalities and essences. |
| 10509 | Understanding consists entirely of grasping abstracted species [Aquinas] |
| Full Idea: Of the thing understood all that is within the actually understanding intellect is the abstracted intelligible species. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Q85 Art2) | |
| A reaction: Abstraction is never supposed to be a luxury bolt-on, but is always seen (in this tradition, and presumably in the modern one), as essential to the intellect, and its way of coming to understand the world. Aristotelian definition is behind this idea. |
| 10506 | Mathematics can be abstracted from sensible matter, and from individual intelligible matter [Aquinas] |
| Full Idea: Intellect can abstract mathematical species from sensible matter, both individual and common. Yet it cannot abstract such species from common intelligible matter, but only from individual intelligible matter. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Q85 Ad2) | |
| A reaction: The idea is that common intelligible matter lacks underlying substance, which is where quantity is to be found. |
| 9094 | Mathematical objects abstract both from perceived matter, and from particular substance [Aquinas] |
| Full Idea: Objects of mathematics abstract from perceived matter both in particular and in general, though from thought matter (substance as underlying quality) only in particular and not in general. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ch.5 Q85.1) | |
| A reaction: This appears to be a thoroughly abstractionist view of the way in which humans create mathematics. Aquinas explicitly denies the Platonic view that the numbers already have abstract existence, awaiting our discovery. |
| 10505 | We can just think of an apple's colour, because the apple is not part of the colour's nature [Aquinas] |
| Full Idea: The apple is not part of the nature of the colour, and so nothing prevents one from understanding the colour while understanding nothing of the apple. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Q85 1 Ad 1) | |
| A reaction: This helps to clarify why the procedure of 'ignoring' features is possible. It suggests that some features might be too entangled with the substance (too essential?) to be thus ignored. I can't think of an example, though. Why not?! |
| 10504 | Abstracting either treats something as separate, or thinks of it separately [Aquinas] |
| Full Idea: Abstracting takes place in two ways: by composition and division, understanding something to be not in another or to be separated from it; and by a simple and unconditioned consideration, understanding one thing while not considering the other at all. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Q85 1 Ad 1) | |
| A reaction: The second way is by 'ignoring', which he says cannot contain error. The first seems to be considering some mode of a thing to be actually separate from the thing, which could clearly be erroneous. Ignoring makes to commitment to a unity. |
| 10507 | Numbers and shapes are abstracted by ignoring their sensible qualities [Aquinas] |
| Full Idea: Quantities such as numbers and dimensions, and also shapes (which are the limits of quantities) can be considered without their sensible qualities, which is for them to be abstracted from sensible matter. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Q85 Ad2) | |
| A reaction: His account relies on underlying substance, which is where quantity is to be found (presumably because a substance is the epitome of a unit). |
| 9096 | The mind must produce by its own power an image of the individual species [Aquinas] |
| Full Idea: The agent mind must itself turn to images, and produce by its own power in the receptive mind a representation as to species of whatever the images represent as individual. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ch.5 Q85.1) | |
| A reaction: Unlike much of this section, this sentence supports Geach's claim that Aquinas agrees with him - that the mind creates its concepts, rather than 'abstracting' them from experience. |
| 13248 | We can rest truth-conditions on situations, rather than on possible worlds [Beall/Restall] |
| Full Idea: Situation semantics is a variation of the truth-conditional approach, taking the salient unit of analysis not to be the possible world, or some complete consistent index, but rather the more modest 'situation'. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.5.4) | |
| A reaction: When I read Davidson (and implicitly Frege) this is what I always assumed was meant. The idea that worlds are meant has crept in to give truth conditions for modal statements. Hence situation semantics must cover modality. |
| 13233 | Propositions commit to content, and not to any way of spelling it out [Beall/Restall] |
| Full Idea: Our talk of propositions expresses commitment to the general notion of content, without a commitment to any particular way of spelling this out. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.1) | |
| A reaction: As a fan of propositions I like this. It leaves open the question of whether the content belongs to the mind or the language. Animals entertain propositions, say I. |
| 23180 | The will is the rational appetite [Aquinas] |
| Full Idea: The will is the rational appetite. | |
| From: Thomas Aquinas (Summa Theologicae [1265], II-II Q58 4) | |
| A reaction: Defining the will in terms of reason sounds more like an Enlightenment optimist than a medieval theologian. I suspect that for him it is tautological the reason is involved, if only the reason can make decisions. Hobbes prefers to ruling appetite. |
| 22112 | For humans good is accordance with reason, and bad is contrary to reason [Aquinas] |
| Full Idea: A human being's good is existing in accordance with reason, while what is bad for a human being is whatever is contrary to reason. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia IIae.Q18.5c), quoted by Kretzmann/Stump - Aquinas, Thomas 13 | |
| A reaction: For anyone who thought Kant invented the idea that morality derives from reason. This idea of Aquinas is a fairly precise echo of the stoic view (which influenced Kant). Is there a circularity? Is it irrational because bad, or bad because irrational? |
| 18681 | The base for values has grounds, catalysts and intensifiers [Dancy,J, by Orsi] |
| Full Idea: Dancy distinguishes three parts of the supervenience base of values: 1) those which ground the value ('resultance base'); 2) those which enable the ground to make something good ('enabling conditions'); 3) those which intensify or diminish value. | |
| From: report of Jonathan Dancy (Ethics without Principles [2004], p. 170-181) by Francesco Orsi - Value Theory 5.2 | |
| A reaction: I really like and admire this. Dancy has focused on what really matters about values (and hence about the whole of ethics), and begun the work of getting a bit of clarity and increased understanding. |
| 22494 | We must know the end, know that it is the end, and know how to attain it [Aquinas] |
| Full Idea: Perfect knowledge of the end consists in not only apprehending the thing which is the end but also knowing it under the aspect of the end and the relation of the means to that end. | |
| From: Thomas Aquinas (Summa Theologicae [1265], II-I.Q132), quoted by Philippa Foot - Natural Goodness 4 | |
| A reaction: We don't talk much now about 'perfect' knowledge of something, but I suppose this is the necessary and sufficient conditions. If you complete the checklist, your knowledge should be perfect (if the list is right). |
| 23181 | All acts of virtue relate to justice, which is directed towards the common good [Aquinas] |
| Full Idea: The good of any virtue …is referable to the common good, to which justice directs, so that all acts of virtue can pertain to justice insofar as it directs man to the common good. | |
| From: Thomas Aquinas (Summa Theologicae [1265], II-II Q58 5) | |
| A reaction: Michael Sandel has recently lamented to fading of the concept of 'the common good' from our moral and political life. In which case this thought of Aquinas takes on great importance. I certainly like it. It seems to apply to courage, for example. |
| 8009 | Aquinas wanted, not to escape desire, but to transform it for moral ends [Aquinas, by MacIntyre] |
| Full Idea: The Aristotelianism of Thomas Aquinas (unlike St Augustine's Platonism) is not concerned with escaping from the snares of the world and of desire, but with transforming desire for moral ends. | |
| From: report of Thomas Aquinas (Summa Theologicae [1265]) by Alasdair MacIntyre - A Short History of Ethics Ch.9 | |
| A reaction: This is very close to Aristotle himself, for whom education of the feelings (into good habits, and then true virtues) was central. Education of feelings should be central to all education (though young psychopaths may show resistance). |
| 23182 | Legal justice is supreme, because it directs the other virtues to the common good [Aquinas] |
| Full Idea: There must be one supreme virtue essentially distinct from every other virtue, which directs all the virtues to the common good, and this virtue is legal justice. | |
| From: Thomas Aquinas (Summa Theologicae [1265], II-II Q58 6) | |
| A reaction: This concept of legal justice is underpinned, for Aquinas, by the concept of natural law, which has divine backing. Positive law could hardly fulfil such a major role, given that it could be corrupt. |
| 22399 | Temperance prevents our passions from acting against reason [Aquinas] |
| Full Idea: The passions may incite us to something against reason, and so we need a curb, which we name 'temperance'. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia 2ae Q61 a.3), quoted by Philippa Foot - Virtues and Vices II | |
| A reaction: I am increasingly unclear what 'reason' means in contexts like these. It seems to mean no more than the awareness of greater goods than the indulgence of passion. Without that awareness, high intelligence couldn't produce temperance. |
| 23177 | Justice directs our relations with others, because it denotes a kind of equality [Aquinas] |
| Full Idea: It is proper to justice, as compared with the other virtues, to direct man in his relations with others, because it denotes a kind of equality, as its very name implies; indeed we are wont to say that things are 'adjusted' when they are made equal. | |
| From: Thomas Aquinas (Summa Theologicae [1265], II-II Q57 1) | |
| A reaction: Even if you say justice is giving people what they deserve, rather than mere equality, they must still be equal in receiving like for like. Legal justice implies equality before the law (except for monarchs?). |
| 23179 | People differ in their social degrees, and a particular type of right applies to each [Aquinas] |
| Full Idea: There are many differences of degrees among men, for instance, some are soldiers, some are priests, some are princes. Therefore some special kind of right should be alloted to them. | |
| From: Thomas Aquinas (Summa Theologicae [1265], II-II Q57 4) | |
| A reaction: An objection (3), but Aquinas endorses it in his reply. In 58.10 he says striking a prince is worse that striking a commoner. The shift to the idea that everyone is supposed to be equal before the law has been slow, and we are not quite there yet. |
| 23174 | Natural law is a rational creature's participation in eternal law [Aquinas] |
| Full Idea: It is evident that the natural law is nothing else than the rational creature's participation of the eternal law. | |
| From: Thomas Aquinas (Summa Theologicae [1265], I-II Q91 2) | |
| A reaction: It is not enough merely that God decrees eternal laws. It is also necessary for us to use reason in order to participate. I'm not sure what reasoning process is involved. |
| 22114 | Tyrannical laws are irrational, and so not really laws [Aquinas] |
| Full Idea: A tyrannical law, since it is not in accord with reason, is not unconditionally a law, but is rather a perversion of law. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia IIae.Q92.1, ad 4), quoted by Kretzmann/Stump - Aquinas, Thomas 13 | |
| A reaction: Only a belief in natural law can give a basis for such a claim. Positivists will say a tyrannical law is unconditionally a law like any other, but a bad one. |
| 22113 | Right and wrong actions pertain to natural law, as perceived by practical reason [Aquinas] |
| Full Idea: All things to be done or to be avoided pertain to the precepts of natural law, which practical reasoning apprehends naturally as being human goods. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia IIae.Q94.2c), quoted by Kretzmann/Stump - Aquinas, Thomas 13 | |
| A reaction: No mention of God, but you feel the divine presence in the background. He also cites 'eternal law'. No coincidence that the atheist Hobbes rejected natural law. Personally I would offer an atheistic defence of natural law, based on human nature. |
| 7291 | For Aquinas a war must be in a just cause, have proper authority, and aim at good [Aquinas, by Grayling] |
| Full Idea: Aquinas argued that on three conditions war can be justified: first, that there is a just cause; second, that it is begun on proper authority; and third, that it is waged with right intention, for 'the advancement of good, or the avoidance of evil'. | |
| From: report of Thomas Aquinas (Summa Theologicae [1265], II) by A.C. Grayling - Among the Dead Cities Ch.6 | |
| A reaction: But see also Idea 7292. Nowadays we are rightly suspicious of all three conditions. Evil people seem to think their cause is just; authority has often been seized by violence, or is being abused; and people seem confused about what is good or evil. |
| 5508 | Aquinas says a fertilized egg is not human, and has no immortal soul [Aquinas, by Martin/Barresi] |
| Full Idea: In Aquinas's view the fertilized egg is not, either at the moment of conception or for quite a while afterwards, endowed with an immortal soul. In fact, technically speaking, it is not even human. | |
| From: report of Thomas Aquinas (Summa Theologicae [1265]) by R Martin / J Barresi - Introduction to 'Personal Identity' p.20 | |
| A reaction: It is pointed at that therefore Aquinas does not give good support for modern Catholic views on abortion. There is certainly no reason why a human zygote should be ensouled from the start, as God may do this whenever He wishes. |
| 16687 | Bodies are three-dimensional substances [Aquinas] |
| Full Idea: Bodies are those substances in which one finds three dimensions. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia Q18.2c), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 16.2 | |
| A reaction: Pasnau points out that this extensional view of physical bodies was a commonplace long before Descartes. Presumably there are also non-dimensional substances (such as angels?). |
| 23178 | Divine law commands some things because they are good, while others are good because commanded [Aquinas] |
| Full Idea: The divine law commands certain things because they are good and forbids others because they are evil, while others are good because they are prescribed, and others evil because they are forbidden. | |
| From: Thomas Aquinas (Summa Theologicae [1265], II-II Q57 2) | |
| A reaction: This is a fifty-fifty response to the Euthyphro dilemma, but it seems to leave the theological puzzle of the source of the goodness which is prescribed because it is in fact good. |
| 21251 | We can't know God's essence, so his existence can't be self-evident for us [Aquinas] |
| Full Idea: Because we do not know the essence of God, the proposition 'God exists' is not self-evident to us, but needs to be demonstrated by things that are more known to us. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Art 1, Obj 3) | |
| A reaction: Depends on his definition of self-evidence (Idea 21250), which needs knowledge of the essence of the subject. Anselm required 'understanding' of the concept. One might understand the existence criteria without knowing the whole essence. Anselm wins. |
| 5614 | If you assume that there must be a necessary being, you can't say which being has this quality [Kant on Aquinas] |
| Full Idea: To those who assume the existence of a necessary being, and would only know which among all things had to be regarded as such a thing, one could not answer: This thing here is the necessary being | |
| From: comment on Thomas Aquinas (Summa Theologicae [1265]) by Immanuel Kant - Critique of Pure Reason A612/B640 | |
| A reaction: See Aquinas in Idea 1431. Kant makes a nice point. You might turn out to be the necessary being? How could you tell? You only know that there must be one lurking somewhere. I could be a slug. Aquinas makes a huge leap to God. |
| 21269 | Way 1: the infinite chain of potential-to-actual movement has to have a first mover [Aquinas] |
| Full Idea: A thing can only be reduced from potentiality to actuality by something actual. A thing can never be in actuality and potentiality in the same respect. So what is moved must be moved by another. But this cannot go on to infinity, with no first mover. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia,Q02,Art3,Reply) | |
| A reaction: [compressed] This relies on the Aristotelian ideas of potentiality and actuality. We might talk about things moving, but lacking the 'power' to move. This is almost identical to Plato in 'The Laws' (which I guess Aquinas knew nothing of). |
| 21270 | Way 2: no effect without a cause, and this cannot go back to infinity, so there is First Cause [Aquinas] |
| Full Idea: If there is no first cause among efficient causes, there is no ultimate or intermediate cause. That in efficient causes it is possible to go on to infinity is plainly false. So it is necessary to admit a first efficient cause, which everyone calls God. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia,Q02,Art3,Reply) | |
| A reaction: [compressed] It doesn't seem to follow at all that the First Cause is God. There could be a single thing like the Phoenix, with unique self-causing properties. Or a quantum fluctuation. |
| 21271 | Way 3: contingent beings eventually vanish, so continuity needs a necessary being [Aquinas] |
| Full Idea: That which can not-be at some time is not. So if everything can not-be, then once there was nothing in existence. If so, it would have been impossible for anything to have begun to exist. So there must be some being having of itself its own necessity. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia,Q02,Art3,Reply) | |
| A reaction: [compressed] Why can't things take it in turns to not-be, so that something is always on duty? Maybe it is a feature of things that they bring other things into existence (e.g. virtual particles)? |
| 21272 | Way 4: the source of all qualities is their maximum, so something (God) causes all perfections [Aquinas] |
| Full Idea: More and less are predicated of different things according as they resemble in their different ways something which is the maximum. The maximum of a genus is the cause of all in that genus. So there must be something causing the perfections of all beings. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia,Q02,Art3,Reply) | |
| A reaction: [compressed] The argument makes a startling jump from each quality (like heat or nobility) having a maximum, to their being a single entity (a 'being' at that) which is the sole source of all human perfections. |
| 21273 | Way 5: mindless things act towards an obvious end, so there is an intelligent director [Aquinas] |
| Full Idea: Things which lack knowledge, such as natural bodies, act for an end, which is usually in the same way, to obtain the best result. Hence they achieve their end designedly. Hence some intelligent being exists by whom all natural things are directed. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia,Q02,Art3,Reply) | |
| A reaction: [compressed] This is Greek teleology with a vengeance. Plants probably illustrate best what he has in mind. There is obvious teleology in human affairs, and there is a sort of teleology in living things, but we take the end to be reinforced by success. |
| 20211 | Life aims at the Beatific Vision - of perfect happiness, and revealed truth [Aquinas, by Zagzebski] |
| Full Idea: Aquinas describes the ultimate end of human life as the Beatific Vision, a state that is simultaneously the enjoyment of perfect happiness and a perfect revelation of truth. | |
| From: report of Thomas Aquinas (Summa Theologicae [1265]) by Linda Trinkaus Zagzebski - Virtues of the Mind II 4.2 | |
| A reaction: I like that a lot, even though my idea of the revelation of truth is very distant from that of Aquinas. Ignorant happiness is not much of an aspiration. |
| 22106 | Aquinas saw angels as separated forms, rather than as made of 'spiritual matter' [Aquinas, by Kretzmann/Stump] |
| Full Idea: Unlike some of his contemporaries, Aquinas does not think that there is a 'spiritual matter' that angels or disembodied souls have as one of their components, but rather that they are separated forms that configure no matter at all. | |
| From: report of Thomas Aquinas (Summa Theologicae [1265]) by Kretzmann/Stump - Aquinas, Thomas 10 | |
| A reaction: 'Separated forms' sounds like the modern concept of abstract entities, meaning that souls and angels exist in the way that platonists believe numbers exist. How else might Aquinas have understood them? |
| 23306 | Humans have a non-physical faculty of reason, so they can be immortal [Aquinas, by Sorabji] |
| Full Idea: Aquinas infers from Aristotle that intellectual understanding is the only operation of the soul that is performed without a physical organ, so that only human souls, and not animal ones, can be immortal. | |
| From: report of Thomas Aquinas (Summa Theologicae [1265], I, q75, a3, resp) by Richard Sorabji - Rationality 'Reason' | |
| A reaction: This shows why so many thinkers are desperate to hang on to dualism, of some sort. Interesting that he only claims partial dualism. |
| 4412 | Those in bliss have their happiness increased by seeing the damned punished [Aquinas] |
| Full Idea: In order that the bliss of the saints may be more delightful for them, and they may render more copious thanks to God for it, it is given to them to see perfectly the punishment of the damned. | |
| From: Thomas Aquinas (Summa Theologicae [1265], III Supp Q94,1), quoted by Friedrich Nietzsche - On the Genealogy of Morals I.§15 | |
| A reaction: This has probably been repudiated by the Church of England. Justice should be seen to be done. Presumably you mustn't gloat, or you join them. |
| 21266 | God does not exist, because He is infinite and good, and so no evil should be discoverable [Aquinas] |
| Full Idea: If one of two contraries be infinite, the other would be altogether destroyed. But the name God means that He is infinite goodness. If therefore God existed there would be no evil discoverable; but there is evil in the world. Therefore God does not exist. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia,Q02,Art3,Ob1) | |
| A reaction: This is not, of course, the opinion of Aquinas. I love the way he states the opposition's arguments so lucidly. The modern problem usually talks of God's omnipotence, rather than infinity. His formulation allows that there might be undiscoverable evil. |
| 21274 | It is part of God's supreme goodness that He brings good even out of evil [Aquinas] |
| Full Idea: As Augustine says, God would not allow any evil to exist in his works, unless he were to bring good even out of evil. It is part of the infinite goodness of God, that He allows evil to exist and out of it produces good. | |
| From: Thomas Aquinas (Summa Theologicae [1265], Ia,Q02,Art3,Ob1rep) | |
| A reaction: Are God's powers so limited that He could not have achieved an equal amount of good without having to indulge in some evil first? |