55 ideas
21405 | Cicero sees wisdom in terms of knowledge, but earlier Stoics saw it as moral [Cicero, by Long] |
Full Idea: Cicero (drawing on Panaetius) treats wisdom as if its province were primarily a disinterested pursuit of knowledge. But earlier Stoics gave purely moral definitions of wisdom. | |
From: report of M. Tullius Cicero (On Duties ('De Officiis') [c.44 BCE], 1.11-20) by A.A. Long - Hellenistic Philosophy 5 | |
A reaction: I would have thought that after long discussion most ancient (and even modern) philosophers would conclude that it is both. The 'intellectualism' of Socrates hovers in the background, implying that healthy knowledge produces virtue. |
20871 | Unfortunately we choose a way of life before we are old enough to think clearly [Cicero] |
Full Idea: At the beginning of adolescence when our deliberative capacities are weak we decide on the way of life that we find attractive. So one gets entangled in a definite manner and pattern of life before one is able to judge which one is best. | |
From: M. Tullius Cicero (On Duties ('De Officiis') [c.44 BCE], 1.117) | |
A reaction: Hence it is important to have lots of means for bailing out of education courses, jobs, and even marriage. At least university postpones the key life choices till the early twenties. |
6052 | Definitions identify two concepts, so they presuppose identity [McGinn] |
Full Idea: Any definition must presuppose the notion of identity precisely because a definition affirms the identity of two concepts. | |
From: Colin McGinn (Logical Properties [2000], Ch.1) | |
A reaction: McGinn is arguing that identity is fundamental to thought, and this seems persuasive. It may be, though, that while identities are inescapable, definitions are impossible. |
6064 | Regresses are only vicious in the context of an explanation [McGinn] |
Full Idea: Regresses are only vicious in the context of some explanatory aim, not in themselves. | |
From: Colin McGinn (Logical Properties [2000], Ch.2 n11) | |
A reaction: A nice point. It is not quite clear how 'pure' reason could ever be vicious, or charming, or sycophantic. The problem about a vicious regress is precisely that it fails to explain anything. Now benign regresses are something else… (see Idea 2523) |
6088 | Truth is a method of deducing facts from propositions [McGinn] |
Full Idea: Truth is essentially a method of deducing facts from propositions. | |
From: Colin McGinn (Logical Properties [2000], Ch.5) | |
A reaction: Very persuasive. McGinn is offering a disquotational account of truth, but in a robust form. Of course, deduction normally takes the form of moving infallibly from one truth to another, but that model of deduction won't fit this particular proposal. |
6084 | 'Snow does not fall' corresponds to snow does fall [McGinn] |
Full Idea: We can say that the proposition that snow does not fall from the sky corresponds to the fact that snow does fall from the sky - in the sense that there is a mapping from fact to proposition. | |
From: Colin McGinn (Logical Properties [2000], Ch.5) | |
A reaction: A very nice difficulty for the correspondence theory. It becomes essential to say how the two things correspond before it can offer any sort of account of the truth-relation. |
6085 | The idea of truth is built into the idea of correspondence [McGinn] |
Full Idea: The correspondence theory has an air of triviality, and hence undeniability, but this is because it implicitly builds the idea of truth into the notion of correspondence. | |
From: Colin McGinn (Logical Properties [2000], Ch.5) | |
A reaction: If this is accepted, it is a really fatal objection to the theory. Russell tried to use the idea of 'congruency' between beliefs and reality, but that may be open to the same objection. McGinn is claiming that truth is essentially indefinable. |
6083 | The coherence theory of truth implies idealism, because facts are just coherent beliefs [McGinn] |
Full Idea: If 'snow falls from the sky' is true iff it coheres with other beliefs, this is a form of idealism; snow could surely fall from sky even if there were no beliefs in the world to cohere with each other. | |
From: Colin McGinn (Logical Properties [2000], Ch.5) | |
A reaction: The coherence theory of truth strikes me as yet another blunder involving a confusion of ontology and epistemology. Of course, idealism may be true, but I have yet to hear a good reason why I should abandon commonsense realism. |
6086 | Truth is the property of propositions that makes it possible to deduce facts [McGinn] |
Full Idea: Truth is a property of a proposition from which one can deduce the fact stated by the proposition. | |
From: Colin McGinn (Logical Properties [2000], Ch.5) | |
A reaction: This is McGinn's explanation of the disquotational account of truth ('p' is true iff p). The redundancy theorist would reply that you can deduce p from 'p' without mentioning truth, but it remains to ask why this deduction is possible. |
6087 | Without the disquotation device for truth, you could never form beliefs from others' testimony [McGinn] |
Full Idea: Imagine being in a community which had no concept of truth; ..you cannot disquote on p and hence form beliefs about the world as a result of testimony, since you lack the device of disquotation that is the essence of truth. | |
From: Colin McGinn (Logical Properties [2000], Ch.5) | |
A reaction: Whether his theory is right or not, the observation that testimony is the really crucial area where we must have a notion of truth is very good. How about 'truth is what turns propositions into beliefs'? |
10147 | The Axiom of Choice is consistent with the other axioms of set theory [Feferman/Feferman] |
Full Idea: In 1938 Gödel proved that the Axiom of Choice is consistent with the other axioms of set theory. | |
From: Feferman / Feferman (Alfred Tarski: life and logic [2004], Int I) | |
A reaction: Hence people now standardly accept ZFC, rather than just ZF. |
10148 | Axiom of Choice: a set exists which chooses just one element each of any set of sets [Feferman/Feferman] |
Full Idea: Zermelo's Axiom of Choice asserts that for any set of non-empty sets that (pairwise) have no elements in common, then there is a set that 'simultaneously chooses' exactly one element from each set. Note that this is an existential claim. | |
From: Feferman / Feferman (Alfred Tarski: life and logic [2004], Int I) | |
A reaction: The Axiom is now widely accepted, after much debate in the early years. Even critics of the Axiom turn out to be relying on it. |
10149 | Platonist will accept the Axiom of Choice, but others want criteria of selection or definition [Feferman/Feferman] |
Full Idea: The Axiom of Choice seems clearly true from the Platonistic point of view, independently of how sets may be defined, but is rejected by those who think such existential claims must show how to pick out or define the object claimed to exist. | |
From: Feferman / Feferman (Alfred Tarski: life and logic [2004], Int I) | |
A reaction: The typical critics are likely to be intuitionists or formalists, who seek for both rigour and a plausible epistemology in our theory. |
10150 | The Trichotomy Principle is equivalent to the Axiom of Choice [Feferman/Feferman] |
Full Idea: The Trichotomy Principle (any number is less, equal to, or greater than, another number) turned out to be equivalent to the Axiom of Choice. | |
From: Feferman / Feferman (Alfred Tarski: life and logic [2004], Int I) | |
A reaction: [He credits Sierpinski (1918) with this discovery] |
10146 | Cantor's theories needed the Axiom of Choice, but it has led to great controversy [Feferman/Feferman] |
Full Idea: The Axiom of Choice is a pure existence statement, without defining conditions. It was necessary to provide a foundation for Cantor's theory of transfinite cardinals and ordinal numbers, but its nonconstructive character engendered heated controversy. | |
From: Feferman / Feferman (Alfred Tarski: life and logic [2004], Int I) |
6051 | In 'x is F and x is G' we must assume the identity of x in the two statements [McGinn] |
Full Idea: If we say 'for some x, x is F and x is G' we are making tacit appeal to the idea of identity in using 'x' twice here: it has to be the same object that is both F and G. | |
From: Colin McGinn (Logical Properties [2000], Ch.1) | |
A reaction: This may well be broadened to any utterances whatsoever. The only remaining question is to speculate about whether it is possible to think without identities. The Hopi presumably gave identity to processes rather objects. How does God think? |
6055 | Both non-contradiction and excluded middle need identity in their formulation [McGinn] |
Full Idea: To formulate the law of non-contradiction ('nothing can be both F and non-F') and the law of excluded middle ('everything is either F or it is not-F'), we need the concept of identity (in 'nothing' and 'everything'). | |
From: Colin McGinn (Logical Properties [2000], Ch.1) | |
A reaction: Two good examples in McGinn's argument that identity is basic to all thinking. But the argument also works to say that necessity is basic (since both laws claim it) and properties are basic. Let's just declare everything 'basic', and we can all go home. |
6059 | Identity is unitary, indefinable, fundamental and a genuine relation [McGinn] |
Full Idea: I have endorsed four main theses about identity: it is unitary, it is indefinable, it is fundamental, and it is a genuine relation | |
From: Colin McGinn (Logical Properties [2000], Ch.1) | |
A reaction: That it is fundamental to our thinking seems certain (but to all possible thought?). That it is a relation looks worth questioning. One might challenge unitary by comparing the identity of numbers, values, electrons and continents. I can't define it. |
6042 | The quantifier is overrated as an analytical tool [McGinn] |
Full Idea: The quantifier has been overrated as a tool of logical and linguistic analysis. | |
From: Colin McGinn (Logical Properties [2000], Pref) | |
A reaction: I find this proposal quite thrilling. Twentieth century analytical philosophy has been in thrall to logic, giving the upper hand in philosophical discussion to the logicians, who are often not very good at philosophy. |
6067 | Existential quantifiers just express the quantity of things, leaving existence to the predicate 'exists' [McGinn] |
Full Idea: What the existential quantifier does is indicate the quantity of things in question - it says that some are; it is left up to the predicate 'exists' to express existence. | |
From: Colin McGinn (Logical Properties [2000], Ch.2) | |
A reaction: This seems right. The whole quantification business seems like a conjuring trick to conceal the embarrassingly indefinable and 'metaphysical' notion of 'existence'. Cf Idea 7697. |
6069 | 'Partial quantifier' would be a better name than 'existential quantifier', as no existence would be implied [McGinn] |
Full Idea: We would do much better to call 'some' the 'partial quantifier' (rather than the 'existential quantifier'), on analogy with the universal quantifier - as neither of them logically implies existence. | |
From: Colin McGinn (Logical Properties [2000], Ch.2) | |
A reaction: Like McGinn's other suggestions in this chapter, this strikes me as a potentially huge clarification in linguistic analysis. I wait with interest to see whether the philosophical logicians take it up. I bet they don't. |
6068 | We need an Intentional Quantifier ("some of the things we talk about.."), so existence goes into the proposition [McGinn] |
Full Idea: We could introduce an 'intentional quantifier' (Ix) which means 'some of the things we talk about..'; we could then say 'some of the things we talk about are F and exist' (Ix, x is F and x exists). | |
From: Colin McGinn (Logical Properties [2000], Ch.2) | |
A reaction: This immediately strikes me as a promising contribution to the analytical toolkit. McGinn is supporting his view that existence is a predicate, and so belongs inside the proposition, not outside. |
10158 | A structure is a 'model' when the axioms are true. So which of the structures are models? [Feferman/Feferman] |
Full Idea: A structure is said to be a 'model' of an axiom system if each of its axioms is true in the structure (e.g. Euclidean or non-Euclidean geometry). 'Model theory' concerns which structures are models of a given language and axiom system. | |
From: Feferman / Feferman (Alfred Tarski: life and logic [2004], Int V) | |
A reaction: This strikes me as the most interesting aspect of mathematical logic, since it concerns the ways in which syntactic proof-systems actually connect with reality. Tarski is the central theoretician here, and his theory of truth is the key. |
10162 | Tarski and Vaught established the equivalence relations between first-order structures [Feferman/Feferman] |
Full Idea: In the late 1950s Tarski and Vaught defined and established basic properties of the relation of elementary equivalence between two structures, which holds when they make true exactly the same first-order sentences. This is fundamental to model theory. | |
From: Feferman / Feferman (Alfred Tarski: life and logic [2004], Int V) | |
A reaction: This is isomorphism, which clarifies what a model is by giving identity conditions between two models. Note that it is 'first-order', and presumably founded on classical logic. |
10160 | Löwenheim-Skolem says if the sentences are countable, so is the model [Feferman/Feferman] |
Full Idea: The Löwenheim-Skolem Theorem, the earliest in model theory, states that if a countable set of sentences in a first-order language has a model, then it has a countable model. | |
From: Feferman / Feferman (Alfred Tarski: life and logic [2004], Int V) | |
A reaction: There are 'upward' (sentences-to-model) and 'downward' (model-to-sentences) versions of the theory. |
10159 | Löwenheim-Skolem Theorem, and Gödel's completeness of first-order logic, the earliest model theory [Feferman/Feferman] |
Full Idea: Before Tarski's work in the 1930s, the main results in model theory were the Löwenheim-Skolem Theorem, and Gödel's establishment in 1929 of the completeness of the axioms and rules for the classical first-order predicate (or quantificational) calculus. | |
From: Feferman / Feferman (Alfred Tarski: life and logic [2004], Int V) |
10161 | If a sentence holds in every model of a theory, then it is logically derivable from the theory [Feferman/Feferman] |
Full Idea: Completeness is when, if a sentences holds in every model of a theory, then it is logically derivable from that theory. | |
From: Feferman / Feferman (Alfred Tarski: life and logic [2004], Int V) |
10156 | 'Recursion theory' concerns what can be solved by computing machines [Feferman/Feferman] |
Full Idea: 'Recursion theory' is the subject of what can and cannot be solved by computing machines | |
From: Feferman / Feferman (Alfred Tarski: life and logic [2004], Ch.9) | |
A reaction: This because 'recursion' will grind out a result step-by-step, as long as the steps will 'halt' eventually. |
10155 | Both Principia Mathematica and Peano Arithmetic are undecidable [Feferman/Feferman] |
Full Idea: In 1936 Church showed that Principia Mathematica is undecidable if it is ω-consistent, and a year later Rosser showed that Peano Arithmetic is undecidable, and any consistent extension of it. | |
From: Feferman / Feferman (Alfred Tarski: life and logic [2004], Int IV) |
6070 | Existence is a primary quality, non-existence a secondary quality [McGinn] |
Full Idea: Existence is like a primary quality; non-existence is like a secondary quality. | |
From: Colin McGinn (Logical Properties [2000], Ch.2 n29) | |
A reaction: Since McGinn thinks existence really is a property, and hence, presumably, a predicate, I don't quite see why he uses the word "like". A nicely pithy and thought-provoking remark. |
6062 | Existence can't be analysed as instantiating a property, as instantiation requires existence [McGinn] |
Full Idea: Paraphrasing existence statements into statements about the instantiation of a property does not establish that existence is not a predicate, since the notion of instantiation must be taken to have existence built into it. | |
From: Colin McGinn (Logical Properties [2000], Ch.2) | |
A reaction: Thank you, Colin McGinn! This now strikes me as so obvious that it is astonishing that for the whole of the twentieth century no one seems to have said it. For a century philosophers had swept the ontological dirt under the mat. |
6065 | We can't analyse the sentence 'something exists' in terms of instantiated properties [McGinn] |
Full Idea: The problems of the orthodox view are made vivid by analysis of the sentence 'something exists'; this is meaningful and true, but what property are we saying is instantiated here? | |
From: Colin McGinn (Logical Properties [2000], Ch.2) | |
A reaction: A very nice point. McGinn claims that existence is a property, a very generalised one. Personally I don't think anyone is even remotely clear what a property is, so the whole discussion is a bit premature. Must properties have causal powers? |
6082 | If causal power is the test for reality, that will exclude necessities and possibilities [McGinn] |
Full Idea: Whether my body weight is necessary or contingent makes no difference at all to my causal powers, so modality is epiphenomenal; if you took causal potential as a test of reality you would have to declare modes unreal. | |
From: Colin McGinn (Logical Properties [2000], Ch.4) | |
A reaction: We could try analysing modality into causal terms, as Lewis proposes with quantification across worlds, or as Quine proposes by reduction to natural regularities. I am not sure what it would mean to declare that modes are 'real'. |
6075 | Facts are object-plus-extension, or property-plus-set-of-properties, or object-plus-property [McGinn] |
Full Idea: A fact may be an object and an extension (Quine's view), or a property and a set of properties, or an object and a property; the view I favour is the third one, which seems the most natural. | |
From: Colin McGinn (Logical Properties [2000], Ch.3) | |
A reaction: Personally I tend to use the word 'fact' in a realist and non-linguistic way. There must be innumerable inexpressible facts, such as the single pattern made by all the particles of the universe. McGinn seems to be talking of 'atomic facts'. See Idea 6111. |
6058 | Identity propositions are not always tautological, and have a key epistemic role [McGinn] |
Full Idea: Identity propositions are not always analytic or a priori (as Frege long ago taught us) so there is nothing trivial about such propositions; the claim of redundancy ignores the epistemic role that the concept of identity plays. | |
From: Colin McGinn (Logical Properties [2000], Ch.1) | |
A reaction: He is referring to Frege's Morning Star/Evening Star distinction (Idea 4972). Wittgenstein wanted to eliminate our basic metaphysics by relabelling it as analytic or tautological, but his project failed. Long live metaphysics! |
6053 | Identity is as basic as any concept could ever be [McGinn] |
Full Idea: Identity has a universality and basicness that is hard to overstate; concepts don't get more basic than this - or more indispensable. | |
From: Colin McGinn (Logical Properties [2000], Ch.1) | |
A reaction: I agree with this. It seems to me to follow that the natural numbers are just as basic, because they are entailed by the separateness of the identities of things. And the whole of mathematics is the science of the patterns within these numbers. |
6043 | Type-identity is close similarity in qualities [McGinn] |
Full Idea: Two things are said to be type-identical when they are similar enough to be declared qualitatively identical. | |
From: Colin McGinn (Logical Properties [2000], Ch.1) | |
A reaction: A simple point which brings out the fact that type-identity is unlikely to be any sort of true identity (unless there is absolutely no different at all between two electrons, say). |
6044 | Qualitative identity is really numerical identity of properties [McGinn] |
Full Idea: A statement of so-called qualitative identity is really a statement of numerical identity (that is, identity tout court) about the properties of the objects in question - assuming that there are genuine universals. | |
From: Colin McGinn (Logical Properties [2000], Ch.1) | |
A reaction: We might agree that two cars are type-identical, even though (under the microscope) we decided that none of their properties were absolutely identical. |
6046 | Qualitative identity can be analysed into numerical identity of the type involved [McGinn] |
Full Idea: We can analyse qualitative identity in terms of numerical identity, by saying that x and y are type-identical if there is a single type T that x and y both are, i.e. they both exemplify the same type. | |
From: Colin McGinn (Logical Properties [2000], Ch.1) | |
A reaction: This just seems to shift the problem onto the words 'are' and 'exemplify'. This takes us back to the problem of things 'partaking' of Plato's Forms. Better to say that qualitative identity isn't identity - it is resemblance (see Idea 6045). |
6045 | It is best to drop types of identity, and speak of 'identity' or 'resemblance' [McGinn] |
Full Idea: It would be better to drop talk of 'numerical' and 'qualitative' identity altogether, speaking instead simply of identity and resemblance. | |
From: Colin McGinn (Logical Properties [2000], Ch.1 n4) | |
A reaction: This is the kind of beautifully simple proposal I pay analytical philosophers to come up with. I will attempt in future to talk either of 'identity' (which is strict), or 'resemblance' (which comes in degrees). |
6066 | Existence is a property of all objects, but less universal than self-identity, which covers even conceivable objects [McGinn] |
Full Idea: Existence is a property universal to all objects that exist, somewhat like self-identity, but less universal, because self-identity holds of all conceivable objects, not merely those that happen to exist. | |
From: Colin McGinn (Logical Properties [2000], Ch.2) | |
A reaction: This is a splendidly defiant response to the Kantian slogan that 'existence is not a predicate', and I find McGinn persuasive. I can still not find anyone to explain to me exactly what a property is, so I will reserve judgement. |
6054 | Sherlock Holmes does not exist, but he is self-identical [McGinn] |
Full Idea: Sherlock Holmes does not exist, but he is self-identical (he is certainly not indentical to Dr Watson). | |
From: Colin McGinn (Logical Properties [2000], Ch.1) | |
A reaction: Most significant. Identity does not entail existence; identity is necessary for existence (I think) but not sufficient. But the notion of existence might be prior to the notion of identity, and the creation of Holmes be parasitic on real existence. |
6047 | All identity is necessary, though identity statements can be contingently true [McGinn] |
Full Idea: All identity is necessary, although there can be contingently true identity statements - those that contain non-rigid designators. | |
From: Colin McGinn (Logical Properties [2000], Ch.1 n5) | |
A reaction: A nice case of the need to keep epistemology and ontology separate. An example might be 'The Prime Minister wears a wig', where 'Prime Minister' may not be a rigid designator. 'Winston wears a wig' will be necessary, if true (which it wasn't). |
6049 | Leibniz's Law says 'x = y iff for all P, Px iff Py' [McGinn] |
Full Idea: Leibniz's Law says 'x = y iff for all P, Px iff Py'. | |
From: Colin McGinn (Logical Properties [2000], Ch.1) | |
A reaction: That is, two things are the same if when we say that one thing (x) has a property (P), then we are saying that the other thing (y) also has the property. A usefully concise statement of the Law. |
6048 | Leibniz's Law is so fundamental that it almost defines the concept of identity [McGinn] |
Full Idea: Leibniz's Law, which a defender of relative identity might opt to reject, is so fundamental to the notion of identity that rejecting it amounts to changing the subject. | |
From: Colin McGinn (Logical Properties [2000], Ch.1 n8) | |
A reaction: The Law here is the 'indiscernibility of identicals'. I agree with McGinn, and anyone who loses their grip on this notion of identity strikes me as losing all grip on reality, and threatening their own sanity (well, call it their 'philosophical sanity'). |
6050 | Leibniz's Law presupposes the notion of property identity [McGinn] |
Full Idea: Leibniz's Law presupposes the notion of property identity. | |
From: Colin McGinn (Logical Properties [2000], Ch.1) | |
A reaction: A very important observation, because it leads to recognition of the way in which basic concepts and categories of thought interconnect. Which is more metaphysically basic, identity or properties? It is not easy to say… |
6080 | Modality is not objects or properties, but the type of binding of objects to properties [McGinn] |
Full Idea: Modality has a special ontological category: it consists neither in objects (possible worlds theory) nor in properties (predicate modifier view), but items I have called 'modes', ..which can be hard/soft/rigid/pliable binding of objects to properties. | |
From: Colin McGinn (Logical Properties [2000], Ch.4) | |
A reaction: As so often, McGinn is very persuasive. Essentially he is proposing that modality is adverbial. He associates the middle view with David Wiggins. |
6079 | If 'possible' is explained as quantification across worlds, there must be possible worlds [McGinn] |
Full Idea: If we replace modal words like 'possible' with quantification across worlds, clearly the notion of 'world' must exclude impossible worlds, otherwise 'possibly p' will be true if 'p' holds in an impossible world. | |
From: Colin McGinn (Logical Properties [2000], Ch.4) | |
A reaction: The point here, of course, is that the question is being begged of what 'possible' and 'impossible' actually mean. |
6081 | Necessity and possibility are big threats to the empiricist view of knowledge [McGinn] |
Full Idea: It is clear that modality is a prima-facie threat to the usual kind of naturalistic-causal-empiricist theory of knowledge. | |
From: Colin McGinn (Logical Properties [2000], Ch.4) | |
A reaction: This is why modern empiricists spend of a lot of energy on trying to analyse counterfactuals and laws of nature. Rationalists are much happier to assert necessities a priori, but then they often don't have much basis for their claims. |
6071 | Scepticism about reality is possible because existence isn't part of appearances [McGinn] |
Full Idea: Scepticism about the external world is possible because you can never build existence into the appearances, so it must always be inferred or assumed. | |
From: Colin McGinn (Logical Properties [2000], Ch.2) | |
A reaction: When McGinn's claim that existence is a very universal property begins to produce interesting observations like this, I think we should take it very seriously. |
6077 | Semantics should not be based on set-membership, but on instantiation of properties in objects [McGinn] |
Full Idea: Semantics should not employ the relationship of set-membership between objects and extensions, but rather the relation of instantiation between objects and properties. | |
From: Colin McGinn (Logical Properties [2000], Ch.3) | |
A reaction: At least this means that philosophers won't be required to read fat books on set theory, but they will have to think very carefully about 'instantiation'. A good start is the ideas on 'Partaking' of Platonic Forms in this database (in 'Universals'). |
6074 | Clearly predicates have extensions (applicable objects), but are the extensions part of their meaning? [McGinn] |
Full Idea: We are taught that predicates have extensions - the class of objects of which the predicate is true - which seems hard to deny; but a stronger claim is also made - that extensions are semantically relevant features of predicates. | |
From: Colin McGinn (Logical Properties [2000], Ch.3) | |
A reaction: He cites Quine as a spokesman for this view. McGinn is going on to challenge it, by defending universals. It seems to fit in with other externalist theories of concepts and meanings, none of which seems very appealing to me. |
6031 | The essence of propriety is consistency [Cicero] |
Full Idea: The whole essence of propriety is quite certainly consistency. | |
From: M. Tullius Cicero (On Duties ('De Officiis') [c.44 BCE], 1.110) | |
A reaction: This seems to me the key intuition on which Kant built his deontological ethical theory. However, opponents say the consistency requires principles, and these are the enemies of truly good human behaviour, which involves Aristotle's 'particulars'. |
6072 | If Satan is the most imperfect conceivable being, he must have non-existence [McGinn] |
Full Idea: Satan cannot exist because he is the most imperfect conceivable being, and existence is one of the perfections. | |
From: Colin McGinn (Logical Properties [2000], Ch.2) | |
A reaction: The logic of this seems right to me. Presumably the theologians would hastily deny this as a definition of Satan; he must have some positive qualities (like power) in order to enact his supreme moral imperfections. NIce, though. |
6073 | I think the fault of the Ontological Argument is taking the original idea to be well-defined [McGinn] |
Full Idea: My own suspicion about the Ontological Argument is that the fault lies in taking notions like 'the most perfect, impressive and powerful being conceivable' to be well-defined. | |
From: Colin McGinn (Logical Properties [2000], Ch.2) | |
A reaction: I'm tempted to put it more strongly: the single greatest challenge for the theist with intellectual integrity is to give a clear and coherent definition of God. There must be no internal contradictions, and it must be within the bounds of possibility. |