21 ideas
18365 | If truths are just identical with facts, then truths will make themselves true [David] |
Full Idea: According to the identity theory of truth, a proposition is true if and only if it is identical with a fact. ...This leads to the unacceptable claim that every true proposition makes itself true (because it is identical to its fact). | |
From: Marian David (Truth-making and Correspondence [2009], n 14) |
18362 | Examples show that truth-making is just non-symmetric, not asymmetric [David] |
Full Idea: That 'there is at least one proposition' ...is a case where something makes itself true, which generates a counterexample to the natural assumption that truth-making is asymmetric; truth-making, it seems, is merely non-symmetric. | |
From: Marian David (Truth-making and Correspondence [2009], 4) |
18360 | It is assumed that a proposition is necessarily true if its truth-maker exists [David] |
Full Idea: Friends of the truth-maker principle usually hold that the following states a crucial necessary condition on truth-making: if x makes y true, then, necessarily, if x exists then y is true. | |
From: Marian David (Truth-making and Correspondence [2009], 2) | |
A reaction: My objection is that the proposition y is taken to pre-exist, primly awaiting the facts that will award it 'truth'. An ontology that contains an infinity of propositions, most of which so far lack a truth-value, is incoherent. You can have x, but no y! |
18358 | Two different propositions can have the same fact as truth-maker [David] |
Full Idea: Two different propositions can have the same fact as truth-maker. For example, 'L is happy or L is hungry', and 'L is happy or L is thirsty', which are both made true by the fact that L is happy. | |
From: Marian David (Truth-making and Correspondence [2009], 1) |
18355 | What matters is truth-making (not truth-makers) [David] |
Full Idea: The term 'truthmaker' just labels whatever stands in the truth-making relation to a truth. The truth-making relation is crucial. It would have been just as well to refer to the truth-'maker' principle as the truth-'making' principle. | |
From: Marian David (Truth-making and Correspondence [2009], 1) | |
A reaction: This is well said. The commitment of this theory is to something which makes each proposition true. There is no initial commitment to any theories about what sorts of things do the job. |
18363 | Correspondence theorists see facts as the only truth-makers [David] |
Full Idea: Correspondence theorists are committed to the view that, since truth is correspondence with a fact, only facts can make true propositions true. | |
From: Marian David (Truth-making and Correspondence [2009], 4) |
18356 | Correspondence is an over-ambitious attempt to explain truth-making [David] |
Full Idea: Truth-maker theory says that the attempt by correspondence to fill in the generic truth-maker principle with something more informative fails. It is too ambitious, offering a whole zoo of funny facts that are not needed. | |
From: Marian David (Truth-making and Correspondence [2009], 1) | |
A reaction: A typical funny fact is a disjunctive fact, which makes 'he is hungry or thirsty' true (when it can just be made true by the simple fact that he is thirsty). |
18354 | Correspondence is symmetric, while truth-making is taken to be asymmetric [David] |
Full Idea: Correspondence appears to be a symmetric relation while truth-making appears to be, or is supposed to be, an asymmetric relation. | |
From: Marian David (Truth-making and Correspondence [2009], Intro) |
18364 | Correspondence theory likes ideal languages, that reveal the structure of propositions [David] |
Full Idea: Correspondence theorists tend to promote ideal languages, ...which is intended to mirror perfectly the structure of the propositions it expresses. | |
From: Marian David (Truth-making and Correspondence [2009], n 03) |
18357 | What makes a disjunction true is simpler than the disjunctive fact it names [David] |
Full Idea: The proposition that 'L is happy or hungry' can be made true by the fact that L is happy. This does not have the same complexity or constituent structure as the proposition it makes true. | |
From: Marian David (Truth-making and Correspondence [2009], 1) |
18359 | One proposition can be made true by many different facts [David] |
Full Idea: One proposition can be made true by many different facts (such as 'there are some happy dogs'). | |
From: Marian David (Truth-making and Correspondence [2009], 1) |
18361 | A reflexive relation entails that the relation can't be asymmetric [David] |
Full Idea: An asymmetric relation must be irreflexive: any case of aRa will yield a reductio of the assumption that R is asymmetric. | |
From: Marian David (Truth-making and Correspondence [2009], 4) |
13768 | Validity can preserve certainty in mathematics, but conditionals about contingents are another matter [Edgington] |
Full Idea: If your interest in logic is confined to applications to mathematics or other a priori matters, it is fine for validity to preserve certainty, ..but if you use conditionals when arguing about contingent matters, then great caution will be required. | |
From: Dorothy Edgington (Conditionals [2001], 17.2.1) |
13770 | There are many different conditional mental states, and different conditional speech acts [Edgington] |
Full Idea: As well as conditional beliefs, there are conditional desires, hopes, fears etc. As well as conditional statements, there are conditional commands, questions, offers, promises, bets etc. | |
From: Dorothy Edgington (Conditionals [2001], 17.3.4) |
13764 | Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? [Edgington] |
Full Idea: Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? Are they non-truth-functional, like 'because' or 'before'? Do the values of A and B, in some cases, leave open the value of 'If A,B'? | |
From: Dorothy Edgington (Conditionals [2001], 17.1) | |
A reaction: I would say they are not truth-functional, because the 'if' asserts some further dependency relation that goes beyond the truth or falsity of A and B. Logical ifs, causal ifs, psychological ifs... The material conditional ⊃ is truth-functional. |
13765 | 'If A,B' must entail ¬(A & ¬B); otherwise we could have A true, B false, and If A,B true, invalidating modus ponens [Edgington] |
Full Idea: If it were possible to have A true, B false, and If A,B true, it would be unsafe to infer B from A and If A,B: modus ponens would thus be invalid. Hence 'If A,B' must entail ¬(A & ¬B). | |
From: Dorothy Edgington (Conditionals [2001], 17.1) | |
A reaction: This is a firm defence of part of the truth-functional view of conditionals, and seems unassailable. The other parts of the truth table are open to question, though, if A is false, or they are both true. |
21275 | Unlike a stone, the parts of a watch are obviously assembled in order to show the time [Paley] |
Full Idea: When we come to inspect a watch we perceive (what we could not discover in a stone) that its several parts are put together for a purpose, to produce motion, and that motion so regulated as to point out the hour of the day. | |
From: William Paley (Natural Theology [1802], Ch 1) | |
A reaction: Microscopic examination of the stone would have surprised Paley. Should we infer a geometer because the sun is spherical? Crytals look designed, but are explained by deeper chemistry. |
21276 | From the obvious purpose and structure of a watch we must infer that it was designed [Paley] |
Full Idea: The inference is inevitable that the watch had a maker; that there must have existed, at some time, an artificer or artificers who formed it for the purpose which we find it actually to answer, who designed its use. | |
From: William Paley (Natural Theology [1802], Ch 1) | |
A reaction: It rather begs the question to refer to an ordered structure as a 'design'. Why do we think it is absurd to think the the 'purpose' of the sun is to benefit mankind? Suppose we found a freakish natural sundial in the woods. |
21277 | Even an imperfect machine can exhibit obvious design [Paley] |
Full Idea: It is not necessary that a machine be perfect, in order to show with what design it was made. | |
From: William Paley (Natural Theology [1802], Ch 1) | |
A reaction: This encounters Hume's point that you will then have to infer that the designer contains similar imperfections. If you look at plagues, famines and mothers dying in childbirth (see Mill), you might wish the designer had never started. |
21278 | All the signs of design found in a watch are also found in nature [Paley] |
Full Idea: Every indication of contrivance, every manifestation of design, which existed in the watch, exists in the works of nature. | |
From: William Paley (Natural Theology [1802], Ch.3) | |
A reaction: This is far from obvious. It was crucial to the watch analogy that we immediately see its one self-evident purpose. No one looks at nature and says 'Aha, I know what this is all for'. |
21357 | No organ shows purpose more obviously than the eyelid [Paley] |
Full Idea: The eyelid defends the eye; it wipes it; it closes it in sleep. Are there, in any work of art whatever, purposes more evident than those which this organ fulfils? | |
From: William Paley (Natural Theology [1802], p.24), quoted by Armand Marie LeRoi - The Lagoon: how Aristotle invented science 031 | |
A reaction: Nice to have another example, in addition to the watch. He is not wholly wrong, because it is impossible to give an evolutionary account of the development of the eyelid without referring to some sort of teleological aspect. The eyelid has a function. |