99 ideas
224 | When questions are doubtful we should concentrate not on objects but on ideas of the intellect [Plato] |
Full Idea: Doubtful questions should not be discussed in terms of visible objects or in relation to them, but only with reference to ideas conceived by the intellect. | |
From: Plato (Parmenides [c.364 BCE], 135e) |
232 | Opposites are as unlike as possible [Plato] |
Full Idea: Opposites are as unlike as possible. | |
From: Plato (Parmenides [c.364 BCE], 159a) |
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. |
8937 | Plato's 'Parmenides' is the greatest artistic achievement of the ancient dialectic [Hegel on Plato] |
Full Idea: Plato's 'Parmenides' is the greatest artistic achievement of the ancient dialectic. | |
From: comment on Plato (Parmenides [c.364 BCE]) by Georg W.F.Hegel - Phenomenology of Spirit Pref 71 | |
A reaction: It is a long way from the analytic tradition of philosophy to be singling out a classic text for its 'artistic' achievement. Eventually we may even look back on, say, Kripke's 'Naming and Necessity' and see it in that light. |
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). |
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. |
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. |
13986 | Plato found antinomies in ideas, Kant in space and time, and Bradley in relations [Plato, by Ryle] |
Full Idea: Plato (in 'Parmenides') shows that the theory that 'Eide' are substances, and Kant that space and time are substances, and Bradley that relations are substances, all lead to aninomies. | |
From: report of Plato (Parmenides [c.364 BCE]) by Gilbert Ryle - Are there propositions? 'Objections' |
14150 | Plato's 'Parmenides' is perhaps the best collection of antinomies ever made [Russell on Plato] |
Full Idea: Plato's 'Parmenides' is perhaps the best collection of antinomies ever made. | |
From: comment on Plato (Parmenides [c.364 BCE]) by Bertrand Russell - The Principles of Mathematics §337 |
10242 | I apply structuralism to concrete and abstract objects indiscriminately [Quine] |
Full Idea: My own line is a yet more sweeping structuralism (than David Lewis's account of classes), applying to concrete and abstract objects indiscriminately. | |
From: Willard Quine (Structure and Nature [1992], p.6), quoted by Stewart Shapiro - Philosophy of Mathematics 4.9 | |
A reaction: Shapiro calls this 'breathtaking', and retreats from it, but it is something like my own view, starting from Mill's pebbles and working up. |
16150 | One is, so numbers exist, so endless numbers exist, and each one must partake of being [Plato] |
Full Idea: If one is, there must also necessarily be number - Necessarily - But if there is number, there would be many, and an unlimited multitude of beings. ..So if all partakes of being, each part of number would also partake of it. | |
From: Plato (Parmenides [c.364 BCE], 144a) | |
A reaction: This seems to commit to numbers having being, then to too many numbers, and hence to too much being - but without backing down and wondering whether numbers had being after all. Aristotle disagreed. |
229 | The one was and is and will be and was becoming and is becoming and will become [Plato] |
Full Idea: The one was and is and will be and was becoming and is becoming and will become. | |
From: Plato (Parmenides [c.364 BCE], 155d) |
21821 | Plato's Parmenides has a three-part theory, of Primal One, a One-Many, and a One-and-Many [Plato, by Plotinus] |
Full Idea: The Platonic Parmenides is more exact [than Parmenides himself]; the distinction is made between the Primal One, a strictly pure Unity, and a secondary One which is a One-Many, and a third which is a One-and-Many. | |
From: report of Plato (Parmenides [c.364 BCE]) by Plotinus - The Enneads 5.1.08 | |
A reaction: Plotinus approves of this three-part theory. Parmenides has the problem that the highest Being contains no movement. By placing the One outside Being you can give it powers which an existent thing cannot have. Cf the concept of God. |
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. |
221 | Absolute ideas, such as the Good and the Beautiful, cannot be known by us [Plato] |
Full Idea: The absolute good and the beautiful and all which we conceive to be absolute ideas are unknown to us. | |
From: Plato (Parmenides [c.364 BCE], 134c) |
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. |
10243 | My ontology is quarks etc., classes of such things, classes of such classes etc. [Quine] |
Full Idea: My tentative ontology continues to consist of quarks and their compounds, also classes of such things, classes of such classes, and so on. | |
From: Willard Quine (Structure and Nature [1992], p.9), quoted by Stewart Shapiro - Philosophy of Mathematics 4.9 | |
A reaction: I would call this the Hierarchy of Abstraction (just coined it - what do you think?). Unlike Quine, I don't see why its ontology should include things called 'sets' in addition to the things that make them up. |
223 | If you deny that each thing always stays the same, you destroy the possibility of discussion [Plato] |
Full Idea: If a person denies that the idea of each thing is always the same, he will utterly destroy the power of carrying on discussion. | |
From: Plato (Parmenides [c.364 BCE], 135c) |
227 | You must always mean the same thing when you utter the same name [Plato] |
Full Idea: You must always mean the same thing when you utter the same name. | |
From: Plato (Parmenides [c.364 BCE], 147d) |
211 | If admirable things have Forms, maybe everything else does as well [Plato] |
Full Idea: It is troubling that if admirable things have abstract ideas, then perhaps everything else must have ideas as well. | |
From: Plato (Parmenides [c.364 BCE], 130d) |
228 | Greatness and smallness must exist, to be opposed to one another, and come into being in things [Plato] |
Full Idea: These two ideas, greatness and smallness, exist, do they not? For if they did not exist, they could not be opposites of one another, and could not come into being in things. | |
From: Plato (Parmenides [c.364 BCE], 149e) |
210 | It would be absurd to think there were abstract Forms for vile things like hair, mud and dirt [Plato] |
Full Idea: Are there abstract ideas for such things as hair, mud and dirt, which are particularly vile and worthless? That would be quite absurd. | |
From: Plato (Parmenides [c.364 BCE], 130d) |
16151 | Plato moves from Forms to a theory of genera and principles in his later work [Plato, by Frede,M] |
Full Idea: It seems to me that Plato in the later dialogues, beginning with the second half of 'Parmenides', wants to substitute a theory of genera and theory of principles that constitute these genera for the earlier theory of forms. | |
From: report of Plato (Parmenides [c.364 BCE]) by Michael Frede - Title, Unity, Authenticity of the 'Categories' V | |
A reaction: My theory is that the later Plato came under the influence of the brilliant young Aristotle, and this idea is a symptom of it. The theory of 'principles' sounds like hylomorphism to me. |
219 | If absolute ideas existed in us, they would cease to be absolute [Plato] |
Full Idea: None of the absolute ideas exists in us, because then it would no longer be absolute. | |
From: Plato (Parmenides [c.364 BCE], 133c) |
220 | The concept of a master includes the concept of a slave [Plato] |
Full Idea: Mastership in the abstract is mastership of slavery in the abstract. | |
From: Plato (Parmenides [c.364 BCE], 133e) |
218 | Participation is not by means of similarity, so we are looking for some other method of participation [Plato] |
Full Idea: Participation is not by means of likeness, so we must seek some other method of participation. | |
From: Plato (Parmenides [c.364 BCE], 133a) |
212 | The whole idea of each Form must be found in each thing which participates in it [Plato] |
Full Idea: The whole idea of each form (of beauty, justice etc) must be found in each thing which participates in it. | |
From: Plato (Parmenides [c.364 BCE], 131a) |
215 | If things partake of ideas, this implies either that everything thinks, or that everything actually is thought [Plato] |
Full Idea: If all things partake of ideas, must either everything be made of thoughts and everything thinks, or everything is thought, and so can't think? | |
From: Plato (Parmenides [c.364 BCE], 132c) |
213 | Each idea is in all its participants at once, just as daytime is a unity but in many separate places at once [Plato] |
Full Idea: Just as day is in many places at once, but not separated from itself, so each idea might be in all its participants at once. | |
From: Plato (Parmenides [c.364 BCE], 131b) |
216 | If things are made alike by participating in something, that thing will be the absolute idea [Plato] |
Full Idea: That by participation in which like things are made like, will be the absolute idea, will it not? | |
From: Plato (Parmenides [c.364 BCE], 132e) |
214 | If absolute greatness and great things are seen as the same, another thing appears which makes them seem great [Plato] |
Full Idea: If you regard the absolute great and the many great things in the same way, will not another appear beyond, by which all these must appear to be great? | |
From: Plato (Parmenides [c.364 BCE], 132a) |
217 | Nothing can be like an absolute idea, because a third idea intervenes to make them alike (leading to a regress) [Plato] |
Full Idea: It is impossible for anything to be like an absolute idea, because a third idea will appear to make them alike, and if that is like anything, it will lead to another idea, and so on. | |
From: Plato (Parmenides [c.364 BCE], 133a) |
15851 | Parts must belong to a created thing with a distinct form [Plato] |
Full Idea: The part would not be the part of many things or all, but of some one character ['ideas'] and of some one thing, which we call a 'whole', since it has come to be one complete [perfected] thing composed [created] of all. | |
From: Plato (Parmenides [c.364 BCE], 157d) | |
A reaction: A serious shot by Plato at what identity is. Harte quotes it (125) and shows that 'character' is Gk 'idea', and 'composed' will translate as 'created'. 'Form' links this Platonic passage to Aristotle's hylomorphism. |
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. |
15846 | In Parmenides, if composition is identity, a whole is nothing more than its parts [Plato, by Harte,V] |
Full Idea: At the heart of the 'Parmenides' puzzles about composition is the thesis that composition is identity. Considered thus, a whole adds nothing to an ontology that already includes its parts | |
From: report of Plato (Parmenides [c.364 BCE]) by Verity Harte - Plato on Parts and Wholes 2.5 | |
A reaction: There has to be more to a unified identity that mere proximity of the parts. When do parts come together, and when do they actually 'compose' something? |
15849 | Plato says only a one has parts, and a many does not [Plato, by Harte,V] |
Full Idea: In 'Parmenides' it is argued that a part cannot be part of a many, but must be part of something one. | |
From: report of Plato (Parmenides [c.364 BCE], 157c) by Verity Harte - Plato on Parts and Wholes 3.2 | |
A reaction: This looks like the right way to go with the term 'part'. We presuppose a unity before we even talk of its parts, so we can't get into contradictions and paradoxes about their relationships. |
15850 | Anything which has parts must be one thing, and parts are of a one, not of a many [Plato] |
Full Idea: The whole of which the parts are parts must be one thing composed of many; for each of the parts must be part, not of a many, but of a whole. | |
From: Plato (Parmenides [c.364 BCE], 157c) | |
A reaction: This is a key move of metaphysics, and we should hang on to it. The other way madness lies. |
13259 | It seems that the One must be composed of parts, which contradicts its being one [Plato] |
Full Idea: The One must be composed of parts, both being a whole and having parts. So on both grounds the One would thus be many and not one. But it must be not many, but one. So if the One will be one, it will neither be a whole, nor have parts. | |
From: Plato (Parmenides [c.364 BCE], 137c09), quoted by Kathrin Koslicki - The Structure of Objects 5.2 | |
A reaction: This is the starting point for Plato's metaphysical discussion of objects. It seems to begin a line of thought which is completed by Aristotle, surmising that only an essential structure can bestow identity on a bunch of parts. |
15847 | Two things relate either as same or different, or part of a whole, or the whole of the part [Plato] |
Full Idea: Everything is surely related to everything as follows: either it is the same or different; or, if it is not the same or different, it would be related as part to whole or as whole to part. | |
From: Plato (Parmenides [c.364 BCE], 146b) | |
A reaction: This strikes me as a really helpful first step in trying to analyse the nature of identity. Two things are either two or (actually) one, or related mereologically. |
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. |
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. |
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? |
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. |
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. |
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. |
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. |
222 | Only a great person can understand the essence of things, and an even greater person can teach it [Plato] |
Full Idea: Only a man of very great natural gifts will be able to understand that everything has a class and absolute essence, and an even more wonderful man can teach this. | |
From: Plato (Parmenides [c.364 BCE], 135a) |
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. |
225 | The unlimited has no shape and is endless [Plato] |
Full Idea: The unlimited partakes neither of the round nor of the straight, because it has no ends nor edges. | |
From: Plato (Parmenides [c.364 BCE], 137e) |
233 | Some things do not partake of the One [Plato] |
Full Idea: The others cannot partake of the one in any way; they can neither partake of it nor of the whole. | |
From: Plato (Parmenides [c.364 BCE], 159d) | |
A reaction: Compare Idea 231 |
2062 | The only movement possible for the One is in space or in alteration [Plato] |
Full Idea: If the One moves it either moves spatially or it is altered, since these are the only motions. | |
From: Plato (Parmenides [c.364 BCE], 138b) |
231 | Everything partakes of the One in some way [Plato] |
Full Idea: The others are not altogether deprived of the one, for they partake of it in some way. | |
From: Plato (Parmenides [c.364 BCE], 157c) | |
A reaction: Compare Idea 233. |
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. |
234 | We couldn't discuss the non-existence of the One without knowledge of it [Plato] |
Full Idea: There must be knowledge of the one, or else not even the meaning of the words 'if the one does not exist' would be known. | |
From: Plato (Parmenides [c.364 BCE], 160d) |
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). |
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)? |
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. |
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? |