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Matheus Silva [28]Matheus Martins Silva [1]
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  1.  99
    In Defense of Brogaard-Salerno Stricture.Matheus Silva - 2017 - The Reasoner 11 (7):42.
    Brogaard and Salerno (2008) argued that counter-examples to contraposition, strengthening the antecedent, and hypothetical syllogism involving subjunctive conditionals only seem to work because they involve a contextual fallacy where the context assumed in the premise(s) is illicitly shifted in the conclusion. To avoid such counter-examples they have proposed that the context must remain fixed when evaluating an argument for validity. That is the Brogaard-Salerno Stricture. Tristan Haze (2016), however, has recently objected that intuitively valid argumentative forms such as conjunction introduction (...)
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  2. An Even Simpler Defense of Material Implication.Matheus Silva - manuscript
    Lee Archie argued that if any truth values are consistently assigned to a natural language conditional to which Modus Ponens and Modus Tollens are valid argumentative forms, and affirming the consequent is an invalid argumentative form, this conditional would have the same truth conditions than a material implication. This argument is simple and it requires few assumptions that are relatively uncontroversial. We show that it is possible to extend Archie’s argument to three-valued logics and five-valued logics and vindicate a slightly (...)
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  3. A Contextualist Defence of the Material Account of Indicative Conditionals.Matheus Silva - manuscript
    The material account of indicative conditionals faces a legion of counterexamples that are the bread and butter in any entry about the subject. For this reason, the material account is widely unpopular among conditional experts. I will argue that this consensus was not built on solid foundations, since these counterexamples are contextual fallacies. They ignore a basic tenet of semantics according to which when evaluating arguments for validity we need to maintain the context constant, otherwise any argumentative form can be (...)
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  4.  63
    A Quantificational Analysis of the Liar Paradox.Matheus Silva - manuscript
    It seems that the most common strategy to solve the liar paradox is to argue that liar sentences are meaningless and, consequently, truth-valueless. The other main option that has grown in recent years is the dialetheist view that treats liar sentences as meaningful, truth-apt and true. In this paper I will offer a new approach that does not belong in either camp. I hope to show that liar sentences can be interpreted as meaningful, truth-apt and false, but without engendering any (...)
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  5.  39
    Conditionals All the Way Down.Matheus Silva - manuscript
    It is usually accepted that unconditional statements are clearer and less problematic than conditional ones. This article goes against this popular belief by advancing the contrarian hypothesis that all unconditional statements can be reduced to conditional ones due to the way our assumptions support our assertions. In fact, considering the coherentist process by which most of our different beliefs mutually support themselves, the only genuine example of unconditional statements are cases of self-justified beliefs, but these examples are controversial and few (...)
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  6.  47
    Is Classical Logic Monotonic?Matheus Silva - manuscript
    It is usually accepted that one of the properties of classical logic is monotonicity, which states that the validity of implication is not affected by the addition of new premises. In this piece, I will argue that this common notion is unjustified since it is motivated by a category mistake. The notion of monotonicity is primarily epistemic in character and can’t be meaningfully attributed to a system. This is acutely clear in the contrast of monotonicity with non-monotonicity, which we tend (...)
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  7.  62
    Directional Bias - Why Most Philosophers (Wrongly) Believe Conditionals Are Not Material.Matheus Silva - manuscript
    There is almost a consensus among philosophers that indicative conditionals are not material. Their thought hinges on the idea that if conditionals were material, A → B could be vacuously true even if the truth of A would lead to the falsity of B. But since this consequence is implausible, the material account must be false. I will argue that this point of view is mistaken, since it is motivated by the grammatical form of conditional sentences and the symbols used (...)
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  8. 'If-Then' as a Version of 'Implies'.Matheus Silva - manuscript
    Russell’s role in the controversy about the paradoxes of material implication is usually presented as a tale of how even the greatest minds can fall prey of basic conceptual confusions. Quine accused him of making a silly mistake in Principia Mathematica. He interpreted ‘if-then’ as a version of ‘implies’ and called it material implication. Quine’s accusation is that this decision involved a use-mention fallacy because the antecedent and consequent of ‘if-then’ are used instead of being mentioned as the premise and (...)
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  9.  42
    Conditional Sentences as Implication Statements: A New Approach.Matheus Silva - manuscript
    It is usually accepted that conditional sentences are sui generis and enigmatic. In this paper I try to make them more accessible by interpreting them as claims to relations of implication restricted to a parameter world. This interpretation revives an old idea that fell into disuse, but in its improved version leads to refreshing solutions to known problems in conditional theory. The many benefits of this approach are evidenced by its insightful explanation of some apparent counter-examples to classical argumentative forms (...)
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  10.  67
    Indicative Conditionals Are Material - Expanding the Survey.Matheus Martins Silva - manuscript
    The material account of indicative conditionals states that indicative conditional sentences and the material implication have the same truth conditions. Recently, Adam Rieger has carried out a survey of arguments in favour of the material account. In this paper, I extend this survey by presenting yet more arguments for the material account. On top of presenting more arguments, I also want to argue that it is plausible to extend the material account to subjunctive conditionals. For that reason, the arguments here (...)
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  11.  53
    In Defense of Hypothetical Syllogism.Matheus Silva - manuscript
    Moti Mizrahi (2013) presented a putative counterexample to Hypothetical Syllogism (HS) for indicative conditionals aiming to succeed where previous attempts to refute HS have failed. Lee Walters (2014a) objected that Mizrahi’s putative counterexample results from an inadequate analysis of conditionals with embedded modals, but advanced new putative counterexamples to HS for subjunctive conditionals that are supposed to bypass this issue (Walters, 2014a; 2014b). It is argued that Walter’s analysis of embedded modals is unnecessary to prevent Mizrahi’s putative counterexample, since the (...)
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  12.  33
    Keep All Your Textbooks.Matheus Silva - manuscript
    Akman (2017) argued that our logic textbooks should be burned, since they present a propositional analysis of necessary and sufficient conditions that leads to a contradiction. According to Akman, we should instead adopt a first-order analysis where conditions are interpreted as one-place predicates. I will argue that (1) Akman’s argument fails to show that the propositional analysis of conditions leads to a contradiction, since the negation of a conjunction is not a conjunction with negated conjuncts, but rather a disjunction with (...)
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  13.  29
    Looking for the Missing Antecedent.Matheus Silva - manuscript
    The conclusion of a valid deductive argument is contained in its premises, but the deductive argument can still be informative if the arguer is trying to find the missing premises that together with the accepted premises will ensure the truth of the conclusion. Necessarily true conditionals have a deductive-like character so their consequents are contained in their antecedents. These conditionals can be informative, so we need to find the missing antecedent that makes the connection between the antecedent and the consequent. (...)
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  14.  40
    Liar Sentences Are Truth-Apt.Matheus Silva - manuscript
    Lycan (2010: 617) maintained that if we know about a deductive argument P1, P2…, ∴C that it is valid, this shows that a set containing the premises and the negation of conclusion is internally inconsistent {P1, P2,…, ~C}. Using a similar reasoning, we should conclude that an invalid deductive argument shows that a set containing the premises and the negation of conclusion is internally consistent. This implies that premises and conclusion of any deductive argument are truth-apt. Since it is uncontroversial (...)
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  15.  71
    Making Conditional Speech Acts in the Material Way.Matheus Silva - manuscript
    The conventional wisdom about conditionals claims that (1) conditionals that have non-assertive acts in their consequents, such as commands and promises, are not plausibly interpreted as material implications; (2) the most promising hypothesis about these sentences is conditional-assertion theory, which explains a conditional as a conditional speech act, i.e., a performance of a speech act given the assumption of the antecedent. This hypothesis has far-reaching and revisionist consequences, because conditional speech acts are not synonymous with a proposition with truth conditions. (...)
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  16.  56
    Modus Ponens, Conditional-Circularity and Material Implication.Matheus Silva - manuscript
    The modus ponens can be interpreted as an answer to a circularity charge, but this strategy is only feasible if the additional conditional premise is interpreted as a claim to a material implication. Here’s how it works.
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  17.  40
    Making Sense of Deduction.Matheus Silva - manuscript
    An argument is deductive when the arguer believes the truth of the premises necessitates the truth of the conclusion. A deductive argument is valid when the arguer’s claim is true, i.e., when there are no possible worlds whether the premises are true and the conclusion is false. But in order to evaluate this claim in an accurate manner we need to consider three qualifications that have been repeatedly ignored in the literature, namely, consistency in the attribution of truth values, world (...)
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  18.  72
    Necessary and Sufficient Conditions Are Converse Relations.Matheus Silva - manuscript
    According to the so-called ‘standard theory’ of conditions, the conditionship relation is converse, that is, if A is a sufficient condition for B, B is a necessary condition for A. This theory faces well-known counterexamples that appeal to both causal and other asymmetric considerations. I show that these counterexamples lose their plausibility once we clarify two key components of the standard theory: that to satisfy a condition is to instantiate a property, and that what is usually called ‘conditionship relation’ is (...)
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  19. Papineau's Philosophical Devices [Review]. [REVIEW]Matheus Silva - 2012 - Fundamento 5:147-150.
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  20.  35
    Restricted and Unrestricted Modus Ponens.Matheus Silva - manuscript
    In a typical modus ponens the reasoner will (a) assert that a premise materially implies a conclusion in a given world; (b) assert this premise and (c) infer the conclusion. But this restricted modus ponens has little in common with the unrestricted textbook modus ponens, since the latter claims that there are no possible worlds where: (a’) a premise materially implies a conclusion, (b’) that premise is true and (c’) the conclusion is false. It is clear that this textbook modus (...)
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  21. Rethinking Implicatures.Matheus Silva - manuscript
    This paper advances the following criticisms against the received view of implicatures: (1) implicatures are relations of pragmatic implication and not attempts to convey particular speaker meanings; (2) conversational implicatures are non-cancellable; (3) generalised conversational implicatures and conventional implicatures are necessary to preserve the cooperative assumption by means of a conversational maxim of conveyability; (4) implicatures should be divided in utterance implicatures and assumption implicatures, not speaker implicatures and sentence implicatures; (5) trivial implicatures are genuine implicatures; (6) Grice’s theory of (...)
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  22.  90
    Subjunctive Conditionals Are Material.Matheus Silva - manuscript
    The material account claims that indicative conditionals are material. However, the conventional wisdom even among material account enthusiasts is that the material account cannot be extended to subjunctive conditionals. There are mainly three reasons that motivate this consensus: (1) the belief that if subjunctives were material, most subjunctive conditionals would be vacuously true, which is implausible; (2) its inconsistency with Adam pairs, which suggest that indicative and subjunctive conditionals have different truth conditions; and (3) the belief that it is an (...)
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  23.  41
    The Big Four - Their Interdependence and Limitations.Matheus Silva - manuscript
    Four intuitions are recurrent and influential in theories about conditionals: the Ramsey’s test, the Adams’ Thesis, the Equation, and the robustness requirement. For simplicity’s sake, I call these intuitions ‘the big four’. My aim is to show that: (1) the big four are interdependent; (2) they express our inferential dispositions to employ a conditional on a modus ponens; (3) the disposition to employ conditionals on a modus ponens doesn’t have the epistemic significance that is usually attributed to it, since the (...)
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  24.  39
    Two Degrees of Implication.Matheus Silva - manuscript
    In a material implication the relation of logical consequence is restricted to a world parameter, whereas in a formal implication the relation of logical consequence extends over many worlds. One could infer from this pattern that the material implication should be reduced to formal implication since it is just a restricted version of it, or, inversely, that formal implication should be reduced to material implication since it is an unrestricted version of it. But both reductionist claims would betray a superficial (...)
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  25.  95
    The False Promises of Logic Textbooks - How Logic Has a Much More Limited Role Than People Usually Think.Matheus Silva - manuscript
    Logic textbooks advertise that they can teach how to spot a valid argument by its logical form alone. They also boast having collections with the most basic valid argumentative forms people of flesh and blood can use in deductive matters. Think about this for a moment. These are bold statements. If they were accurate, philosophers would be in higher demand than software engineers and no one would be able to make contributions to theoretical physics without ever taking a logic class. (...)
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  26.  46
    The Inextricable Link Between Conditionals and Logical Consequence.Matheus Silva - manuscript
    There is a profound, but frequently ignored, relationship between the classical conception of logical consequence and the material implication. The first repeats the patterns of the latter, but with a wider modal reach. This relationship suggests that there should be also a connection between the notion of logical consequence and the conditional connective of any given logical system. This implies, among other things, that it is incoherent to propose alternatives to the material implication while maintaining the classical conception of logical (...)
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  27.  72
    The Logical Web - Why Most Alternatives to the Material Account Are Ad Hoc.Matheus Silva - manuscript
    The material account of indicative conditionals states that indicative conditional sentences and the material implication have the same truth conditions. Many conditional logics are motivated by attempts to fix the counter-intuitive aspects associated with the material account. Some counter-intuitive instances of classical argumentative forms, e.g., strengthening of the antecedent, contraposition, and conditional negation, are regarded as evidence that the material account is wrong and that classical logic should be rejected in favour of a new logic system in which these argumentative (...)
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  28.  64
    The Material Account of Conditionals and the Clash Between Intensional and Extensional Evidence.Matheus Silva - manuscript
    Intensional evidence is any reason to accept a proposition that is not the truth values of the proposition accepted or, if it is a complex proposition, its propositional contents. Extensional evidence is non-intensional evidence. Someone can accept a complex proposition, but deny its logical consequences in two circumstances: (1) when her acceptance is based on intensional evidence, while the logical consequences of the proposition presuppose the acceptance of extensional evidence, e.g., she can refuse the logical consequence of a proposition she (...)
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  29.  47
    The Triviality Result is Not Counter-Intuitive.Matheus Silva - manuscript
    The Equation (TE) states that the probability of A → B is the probability of B given A (Jeffrey, 1964: 702–703). Lewis has shown that the acceptance of TE implies that the probability of A → B is the probability of B, which is implausible: the probability of a conditional cannot plausibly be the same as the probability of its consequent, e.g., the probability that the match will light given that is struck is not intuitively the same as the probability (...)
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