41 ideas
12027 | There must be a plausible epistemological theory alongside any metaphysical theory [Forbes,G] |
Full Idea: No metaphysical account which renders it impossible to give a plausible epistemological theory is to be countenanced. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 9.1) | |
A reaction: It is hard to object to this principle, though we certainly don't want to go verificationist, and thus rule out speculations about metaphysics which are beyond any possible knowledge. Some have tried to prove that something must exist (e.g. Jacquette). |
6947 | Metaphysics does not rest on facts, but on what we are inclined to believe [Peirce] |
Full Idea: Metaphysical systems have not usually rested upon any observed facts, or not in any great degree. They are chiefly adopted because their fundamental propositions seem 'agreeable to reason', which means that which we find ourselves inclined to believe. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p.15) | |
A reaction: This leads to Peirce's key claim - that we should allow our beliefs to be formed by something outside of ourselves. I don't share Peirce's contempt for metaphysics, which I take to be about the most abstract presuppositions of our ordinary beliefs. |
6937 | Reason aims to discover the unknown by thinking about the known [Peirce] |
Full Idea: The object of reasoning is to find out, from the consideration of what we already know, something else which we do not know. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p. 7) | |
A reaction: I defy anyone to come up with a better definition of reasoning than that. The emphasis is on knowledge rather than truth, which you would expect from a pragmatist. …Actually the definition doesn't cover conditional reasoning terribly well. |
12005 | The symbol 'ι' forms definite descriptions; (ιx)F(x) says 'the x which is such that F(x)' [Forbes,G] |
Full Idea: We use the symbol 'ι' (Greek 'iota') to form definite descriptions, reading (ιx)F(x) as 'the x which is such that F(x)', or simply as 'the F'. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 4.1) | |
A reaction: Compare the lambda operator in modal logic, which picks out predicates from similar formulae. |
12010 | Is the meaning of 'and' given by its truth table, or by its introduction and elimination rules? [Forbes,G] |
Full Idea: The typical semantic account of validity for propositional connectives like 'and' presupposes that meaning is given by truth-tables. On the natural deduction view, the meaning of 'and' is given by its introduction and elimination rules. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 4.4) |
21492 | Realism is basic to the scientific method [Peirce] |
Full Idea: The fundamental hypothesis of the method of science is this: There are real things, whose characters are entirely independent of our opinion of them. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877]), quoted by Albert Atkin - Peirce 3 'method' | |
A reaction: He admits later that this is only a commitment and not a fact. It seems to me that when you combine this idea with the huge success of science, the denial of realism is crazy. Philosophy has a lot to answer for. |
6949 | If someone doubted reality, they would not actually feel dissatisfaction [Peirce] |
Full Idea: Nobody can really doubt that there are Reals, for, if he did, doubt would not be a source of dissatisfaction. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p.19) | |
A reaction: This rests on Peirce's view that all that really matters is a sense of genuine dissatisfaction, rather than a theoretical idea. So even at the end of Meditation One, Descartes isn't actually worried about whether his furniture exists. |
12023 | Vagueness problems arise from applying sharp semantics to vague languages [Forbes,G] |
Full Idea: It is very plausible that the sorites paradoxes arose from the application of a semantic apparatus appropriate only for sharp predicates to languages containing vague predicates (rather than from deficiency of meaning, or from incoherence). | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 7.3) | |
A reaction: Sounds wrong. Of course, logic has been designed for sharp predicates, and natural languages are awash with vagueness. But the problems of vagueness bothered lawyers long before logicians like Russell began to worry about it. |
12017 | In all instances of identity, there must be some facts to ensure the identity [Forbes,G] |
Full Idea: For each instance of identity or failure of identity, there must be facts in virtue of which that instance obtains. ..Enough has been said to lend this doctrine some plausibility. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.5) | |
A reaction: Penelope Mackie picks this out from Forbes as a key principle. It sounds to be in danger of circularity, unless the 'facts' can be cited without referring to, or implicitly making use of, identities - which seems unlikely. |
12024 | If we combined two clocks, it seems that two clocks may have become one clock. [Forbes,G] |
Full Idea: If we imagine a possible world in which two clocks in a room make one clock from half the parts of each, the judgement 'these two actual clocks could have been a single clock' does not seem wholly false. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 7.4) | |
A reaction: You would, of course, have sufficient parts left over to make a second clock, so they look like a destroyed clock, so I don't think I find Forbes's intuition on this one very persuasive. |
11885 | Only individual essences will ground identities across worlds in other properties [Forbes,G, by Mackie,P] |
Full Idea: Forbes argues that, unless we posit individual essences, we cannot guarantee that identities across possible worlds will be appropriately grounded in other properties. | |
From: report of Graeme Forbes (The Metaphysics of Modality [1985]) by Penelope Mackie - How Things Might Have Been 2.4 | |
A reaction: There is a confrontation between Wiggins, who says identity is primitive, and Forbes, who says identity must be grounded in other properties. I think I side with Forbes. |
12014 | An individual essence is a set of essential properties which only that object can have [Forbes,G] |
Full Idea: An individual essence of an object x is a set of properties I which satisfies the following conditions: i. every property P in I is an essential property of x; ii. it is not possible that some object y distinct from x has every member of I. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
A reaction: I am coming to the view that stable natural kinds (like electrons or gold) do not have individual essences, but complex kinds (like tigers or tables) do. The view is based on the idea that explanatory power is what individuates an essence. |
12015 | Non-trivial individual essence is properties other than de dicto, or universal, or relational [Forbes,G] |
Full Idea: A non-trivial individual essence is properties other than a) those following from a de dicto truth, b) properties of existence and self-identity (or their cognates), c) properties derived from necessities in some other category. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
A reaction: [I have compressed Forbes] Rather than adding all these qualificational clauses to our concept, we could just tighten up on the notion of a property, saying it is something which is causally efficacious, and hence explanatory. |
12013 | Essential properties depend on a category, and perhaps also on particular facts [Forbes,G] |
Full Idea: The essential properties of a thing will typically depend upon what category of thing it is, and perhaps also on some more particular facts about the thing itself. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
A reaction: I see no way of dispensing with the second requirement, in the cases of complex entities like animals. If all samples are the same, then of course we can define a sample's essence through its kind, but not if samples differ in any way. |
12012 | Essential properties are those without which an object could not exist [Forbes,G] |
Full Idea: An essential property of an object x is a property without possessing which x could not exist. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
A reaction: This is certainly open to question. See Joan Kung's account of Aristotle on essence. I am necessarily more than eight years old (now), and couldn't exist without that property, but is the property part of my essence? |
12025 | Artefacts have fuzzy essences [Forbes,G] |
Full Idea: Artefacts can be ascribed fuzzy essences. ...We might say that it is essential to an artefact to have 'most' of its parts. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 7.6) | |
A reaction: I think I prefer to accept the idea that essences are unstable things, in all cases. For all we know, electrons might subtly change their general character, or cease to be uniform, tomorrow. Essences explain, and what needs explaining changes. |
12022 | Same parts does not ensure same artefact, if those parts could constitute a different artefact [Forbes,G] |
Full Idea: Sameness of parts is not sufficient for identity of artefacts at a world, since the very same parts may turn up at different times as the parts of artefacts with different designs and functions. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 7.2) | |
A reaction: Thus the Ship of Theseus could be dismantled and turned into a barn (as happened with the 'Mayflower'). They could then be reconstituted as the ship, which would then have two beginnings (as Chris Hughes has pointed out). |
12020 | An individual might change their sex in a world, but couldn't have differed in sex at origin [Forbes,G] |
Full Idea: In the time of a single world, the same individual can undergo a change of sex, but it is less clear that an individual of one sex could have been, from the outset, an individual of another. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 6.5) | |
A reaction: I don't find this support for essentiality of origin very persuasive. I struggle with these ideas. Given my sex yesterday, then presumably I couldn't have had a different sex yesterday. Given that pigs can fly, pigs can fly. What am I missing? |
11888 | Identities must hold because of other facts, which must be instrinsic [Forbes,G, by Mackie,P] |
Full Idea: Forbes has two principles of identity, which we can call the No Bare Identities Principle (identities hold in virtue of other facts), and the No Extrinsic Determination Principle (that only intrinsic facts of a thing establish identity). | |
From: report of Graeme Forbes (The Metaphysics of Modality [1985], 127-8) by Penelope Mackie - How Things Might Have Been 2.7 | |
A reaction: The job of the philosopher is to prise apart the real identities of things from the way in which we conceive of identities. I take these principles to apply to real identities, not conceptual identities. |
12003 | De re modal formulae, unlike de dicto, are sensitive to transworld identities [Forbes,G] |
Full Idea: The difference between de re and de dicto formulae is a difference between formulae which are, and formulae which are not, sensitive to the identities of objects at various worlds. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 3.1) |
12028 | De re necessity is a form of conceptual necessity, just as de dicto necessity is [Forbes,G] |
Full Idea: De re necessity does not differ from de dicto necessity in respect of how it arises: it is still a form of conceptual necessity. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 9.4) | |
A reaction: [Forbes proceeds to argue for this claim] Forbes defends a form of essentialism, but takes the necessity to arise from a posteriori truths because of the a priori involvement of other concepts (rather as Kripke argues). |
12008 | Unlike places and times, we cannot separate possible worlds from what is true at them [Forbes,G] |
Full Idea: There is no means by which we might distinguish a possible world from what is true at it. ...Whereas our ability to separate a place, or a time, from its occupier is crucial to realism about places and times, as is a distance relation. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 4.2) | |
A reaction: He is objecting to Lewis's modal realism. I'm not fully convinced. It depends whether we are discussing real ontology or conceptual space. In the latter I see no difference between times and possible worlds. In ontology, a 'time' is weird. |
12009 | The problem with possible worlds realism is epistemological; we can't know properties of possible objects [Forbes,G] |
Full Idea: The main objection to realism about worlds is from epistemology. Knowledge of properties of objects requires experience of these objects, which must be within the range of our sensory faculties, but only concrete actual objects achieve that. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 4.2) | |
A reaction: This pinpoints my dislike of the whole possible worlds framework, ontologically speaking. I seem to be an actualist. I take possibilities to be inferences to the best explanation from the powers we know of in the actual world. We experience potentiality. |
12007 | Possible worlds are points of logical space, rather like other times than our own [Forbes,G] |
Full Idea: Someone impressed by the parallel between tense and modal operators ...might suggest that just as we can speak of places and times forming their own manifolds or spaces, so we can say that worlds are the points of logical space. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 4.2) | |
A reaction: I particularly like the notion of worlds being "points of logical space", and am inclined to remove it from this context and embrace it as the correct way to understand possible worlds. We must understand logical or conceptual space. |
12011 | Transworld identity concerns the limits of possibility for ordinary things [Forbes,G] |
Full Idea: An elucidation of transworld identity can be regarded as an elucidation of the boundaries of possibility for ordinary things. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
A reaction: I presume that if we don't search for some such criterion, we just have to face the possibility that Aristotle could have been a poached egg in some possible world. To know the bounds of possibility, study the powers of actual objects. |
12016 | The problem of transworld identity can be solved by individual essences [Forbes,G] |
Full Idea: The motivation for investigating individual essences should be obvious, since if every object has such an essence, the problem of elucidating transworld identity can be solved. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 5.1) | |
A reaction: It is important that, if necessary, the identities be 'individual', and not just generic, by sortal, or natural kind. We want to reason about (and explain) truths at the fine-grained level of the individual, not just at the broad level of generalisation. |
12004 | Counterpart theory is not good at handling the logic of identity [Forbes,G] |
Full Idea: The outstanding technical objection to counterpart-theoretic semantics concerns its handling of the logic of identity. In quantified S5 (the orthodox semantics) a = b → □(a = b) is valid, but 'a' must not attach to two objects. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 3.5) |
12021 | Haecceitism attributes to each individual a primitive identity or thisness [Forbes,G] |
Full Idea: Haecceitism attributes to each individual a primitive identity or thisness, as opposed to the sort of essentialism that gives non-trivial conditions sufficient for transworld identity. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 6.6) | |
A reaction: 'Haecceitism' is the doctrine that things have primitive identity. A 'haecceity' is a postulated property which actually does the job. The key point of the view is that whatever it is is 'primitive', and not complex, or analysable. I don't believe it. |
12029 | We believe in thisnesses, because we reject bizarre possibilities as not being about that individual [Forbes,G] |
Full Idea: The natural response to an unreasonable hypothesis of possibility for an object x, that in such a state of affairs it would not be x which satisfies the conditions, is evidence that we do possess concepts of thisness for individuals. | |
From: Graeme Forbes (The Metaphysics of Modality [1985], 9.4) | |
A reaction: We may have a 'concept' of thisness, but we needn't be committed to the 'existence' of a thisness. There is a fairly universal intuition that cessation of existence of an entity when it starts to change can be a very vague matter. |
6940 | The feeling of belief shows a habit which will determine our actions [Peirce] |
Full Idea: The feeling of believing is a more or less sure indication of there being established in our nature some habit which will determine our actions. Doubt never has such an effect. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p.10) | |
A reaction: It is one thing to assert this fairly accurate observation, and another to assert that this is the essence or definition of a belief. Perhaps it is the purpose of belief, without being the phenomenological essence of it. We act in states of uncertainty. |
6943 | A mere question does not stimulate a struggle for belief; there must be a real doubt [Peirce] |
Full Idea: The mere putting of a proposition into the interrogative form does not stimulate the mind to any struggle after belief; there must be a real and living doubt. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p.11) | |
A reaction: This the attractive aspect of Peirce's pragmatism, that he is always focusing on real life rather than abstract theory or pure logic. |
6941 | We are entirely satisfied with a firm belief, even if it is false [Peirce] |
Full Idea: As soon as a firm belief is reached we are entirely satisfied, whether the belief be true or false. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p.10) | |
A reaction: This does not deny that the truth or falsehood of a belief is independent of whether we are satisfied with it. It is making a fair point, though, about why we believe things, and it can't be because of truth, because we don't know how to ensure that. |
6942 | We want true beliefs, but obviously we think our beliefs are true [Peirce] |
Full Idea: We seek for a belief that we shall think to be true; but we think each one of our beliefs to be true, and, indeed, it is mere tautology to say so. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p.11) | |
A reaction: If, as I do, you like to define belief as 'commitment to truth', Peirce makes a rather startling observation. You are rendered unable to ask whether your beliefs are true, because you have defined them as true. Nice point… |
6598 | We need our beliefs to be determined by some external inhuman permanency [Peirce] |
Full Idea: It is necessary that a method should be found by which our beliefs be determined by nothing human, but by some external permanency - by something upon which our thinking has no effect. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877]), quoted by Robert Fogelin - Walking the Tightrope of Reason Ch.5 | |
A reaction: This very sensible and interesting remark hovers somewhere between empiricism and pragmatism. Fogelin very persuasively builds his account of knowledge on it. The key point is that we hardly ever choose what to believe. See Idea 2454. |
6944 | Demonstration does not rest on first principles of reason or sensation, but on freedom from actual doubt [Peirce] |
Full Idea: It is a common idea that demonstration must rest on indubitable propositions, either first principles of a general nature, or first sensations; but actual demonstration is completely satisfactory if it starts from propositions free from all actual doubt. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p.11) | |
A reaction: Another nice example of Peirce focusing on the practical business of thinking, rather than abstract theory. I agree with this approach, that explanation and proof do not aim at perfection and indubitability, but at what satisfies a critical mind. |
6948 | Doubts should be satisfied by some external permanency upon which thinking has no effect [Peirce] |
Full Idea: To satisfy our doubts it is necessary that a method should be found by which our beliefs may be determined by nothing human, but by some external permanency - by something upon which our thinking has no effect. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p.18) | |
A reaction: This may be the single most important idea in pragmatism and in the philosophy of science. See Fodor on experiments (Idea 2455). Put the question to nature. The essential aim is to be passive in our beliefs - just let reality form them. |
6945 | Once doubt ceases, there is no point in continuing to argue [Peirce] |
Full Idea: Some people seem to love to argue a point after all the world is fully convinced of it. But no further advance can be made. When doubt ceases, mental action on the subject comes to an end; and, if it did go on, it would be without purpose. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p.11) | |
A reaction: This is the way Peirce's pragmatism, which deals with how real thinking actually works (rather than abstract logic), deals with scepticism. However, there is a borderline where almost everyone is satisfied, but the very wise person remains sceptical. |
22269 | We must fight fiercely to hang on to the few pleasures which survive into old age [Montaigne] |
Full Idea: I am training and sharpening my appetite for those pleasures that are left. ...We must cling tooth and claw to the use of the pleasures of this life which the advancing years, one after another, rip from our grasp. | |
From: Michel de Montaigne (I.39 On Solitude [1580], p.276) | |
A reaction: That may be one of the most inspiring ideas I have read about pleasure. |
6939 | What is true of one piece of copper is true of another (unlike brass) [Peirce] |
Full Idea: The guiding principle is that what is true of one piece of copper is true of another; such a guiding principle with regard to copper would be much safer than with regard to many other substances - brass, for example. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p. 8) | |
A reaction: Peirce is so beautifully simple and sensible. This gives the essential notion of a natural kind, and is a key notion in our whole understanding of physical reality. |
6938 | Natural selection might well fill an animal's mind with pleasing thoughts rather than true ones [Peirce] |
Full Idea: It is probably of more advantage to an animal to have his mind filled with pleasing and encouraging visions, independently of their truth; and thus, upon unpractical subjects, natural selection might occasion a fallacious tendency of thought. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p. 8) | |
A reaction: Note that this is a pragmatist saying that a set of beliefs might work fine but be untrue. So Peirce does not have the highly relativistic notion of truth of some later pragmatists. Good for him. Note the early date to be thinking about Darwin. |
6946 | If death is annihilation, belief in heaven is a cheap pleasure with no disappointment [Peirce] |
Full Idea: If death is annihilation, then the man who believes that he will certainly go straight to heaven when he dies, provided he have fulfilled certain simple observances in this life, has a cheap pleasure which will not be followed by the least disappointment. | |
From: Charles Sanders Peirce (The Fixation of Belief [1877], p.12) | |
A reaction: This is a nicely wicked summary of one side of Pascal's options. All the problems of the argument are built into Peirce's word "cheap". Peirce goes on to talk about ostriches burying their heads. |