It is a platitude that when we reason, we often take things for granted, sometimes even justifiably so. The chemist might reason from the fact that a substance turns litmus paper red to that substance being an acid. In so doing, they take for granted, reasonably enough, that this test for acidity is valid. We ordinarily reason from things looking a certain way to their being that way. We take for granted, reasonably enough, that things are as they look Although (...) it is a platitude that we often take things for granted when we reason—whether justifiably or not—one might think that we do not have to. In fact, it is a natural expectation that were we not pressed by time, lack of energy or focus, we could always in principle make explicit in the form of premises every single presupposition we make in the course of our reasoning. In other words, it is natural to expect it to be true that presuppositionless reasoning is possible. In this essay, I argue that it is false: presuppositionless reasoning is impossible. Indeed, I think this is one of the lessons of a long-standing paradox about inference and reasoning known as Lewis Carroll’s (1985) regress of the premises. Many philosophers agree that Carroll’s regress teaches us something foundational about reasoning. I part ways about what it is that it teaches us. What it teaches us is that the structure of reasoning is constitutively presuppositional. (shrink)

This thesis brings together two concerns. The first is the nature of inference—what it is to infer—where inference is understood as a distinctive kind of conscious and self-conscious occurrence. The second concern is the possibility of doxastic agency. To be capable of doxastic agency is to be such that one is capable of directly exercising agency over one’s beliefs. It is to be capable of exercising agency over one’s beliefs in a way which does not amount to mere self-manipulation. Subjects (...) who can exercise doxastic agency can settle questions for themselves. A challenge to the possibility of doxastic agency stems from the fact that we cannot believe or come to believe “at will”, where this in turn seems to be so because belief “aims at truth”. It must be explained how we are capable of doxastic agency despite that we cannot believe or come to believe at will. On the orthodox ‘causalist’ conception of inference for an inference to occur is for one act of acceptance to cause another in some specifiable “right way”. This conception of inference prevents its advocates from adequately seeing how reasoning could be a means to exercise doxastic agency, as it is natural to think it is. Suppose, for instance, that one reasons and concludes by inferring where one’s inference yields belief in what one infers. Such an inference cannot be performed at will. We cannot infer at will when inference yields belief any more than we can believe or come to believe at will. When it comes to understanding the extent to which one could be exercising agency in such a case the causalist conception of inference suggests that we must look to the causal history of one’s concluding act of acceptance, the nature of the act’s being determined by the way in which it is caused. What results is a picture on which such reasoning as a whole cannot be action. We are at best capable of actions of a kind which lead causally to belief fixation through “mental ballistics”. The causalist account of inference, I argue, is in fact either inadequate or unmotivated. It either fails to accommodate the self-consciousness of inference or is not best placed to play the very explanatory role which it is put forward to play. On the alternative I develop when one infers one’s inference is the conscious event which is one’s act of accepting that which one is inferring. The act’s being an inference is determined, not by the way it is caused, but by the self-knowledge which it constitutively involves. This corrected understanding of inference renders the move from the challenge to the possibility of doxastic agency to the above ballistics picture no longer tempting. It also yields an account of how we are capable of exercising doxastic agency by reasoning despite being unable to believe or come to believe at will. In order to see how such reasoning could amount to the exercise of doxastic agency it needs to be conceived of appropriately. I suggest that paradigm reasoning which potentially amounts the exercise of doxastic agency ought to be conceived of as primarily epistemic agency—agency the aim of which is knowledge. With inference conceived as suggested, I argue, it can be seen how to engage in such reasoning can just be to successfully exercise such agency. (shrink)

The article develops and justifies, on the basis of the epistemological argumentation theory, two central pieces of the theory of evaluative argumentation interpretation: 1. criteria for recognizing argument types and 2. rules for adding reasons to create ideal arguments. Ad 1: The criteria for identifying argument types are a selection of essential elements from the definitions of the respective argument types. Ad 2: After presenting the general principles for adding reasons (benevolence, authenticity, immanence, optimization), heuristics are proposed for finding missing (...) reasons, for deductive arguments, e.g., semantic tableaux are suggested. (shrink)

Neste artigo trato da questão sobre o que torna uma dedução confiável. Uma resposta satisfatória a tal questão nos ajudaria a entender como dedução pode expandir ou gerar conhecimento. Eu exploro duas respostas a tal questão. A primeira faz uso da noção de acarretamento lógico-formal, enquanto que a segunda faz uso da noção de acarretamento metafísico. A última é superior à primeira, pois nos permite explicar a confiabilidade de uma classe mais ampla de deduções.

In this paper I explore alternative ways of addressing the infinite regress problem of inference, as it was depicted in Lewis Carroll’s ‘What the Tortoise said to Achilles’. Roughly put, the problem is that if a claim to the effect that one’s premises give support to one’s conclusion must itself be part of one’s premises, then an infinite regress of reasons ensues. I discuss some recent attempts to solve that problem, but I find all of them to be wanting. Those (...) attempts either require the reasoner to believe that her premises give support to her conclusion, or to take her premises to give support to her conclusion, where taking is not a doxastic attitude. I conclude that, on the face of the failure of those attempts to solve the problem, there is a strong prima facie case for allowing inference to be blind. (shrink)

Evidentialism as an account of theoretical rationality is a popular and well-defended position. However, recently, it's been argued that misleading higher-order evidence (HOE) – that is, evidence about one's evidence or about one's cognitive functioning – poses a problem for evidentialism. Roughly, the problem is that, in certain cases of misleading HOE, it appears evidentialism entails that it is rational to adopt a belief in an akratic conjunction – a proposition of the form “p, but my evidence doesn't support p” (...) – despite it being the case that believing an akratic conjunction appears to be clearly irrational. In this paper, I diffuse the problem for evidentialism using the distinction between propositional and doxastic rationality. I argue that, although it can be propositionally rational to believe an akratic conjunction (according to evidentialism), one cannot inferentially base an akratic belief in one's evidence, and, thus, one cannot doxastically rationally possess an akratic belief. In addition, I address the worry that my solution to the puzzle commits evidentialists to the possibility of epistemic circumstances in which a proposition, p, is propositionally rational to believe (namely, an akratic conjunction), yet one cannot, in principle, (doxastically) rationally believe p. As I demonstrate, cases of misleading HOE are not the only types of cases that force evidentialists to accept that propositional rationality does not entail the possibility of doxastic rationality. There are no new problems raised by misleading HOE that weren't already present in cases involving purely first-order evidence. (shrink)

People frequently report that, at times, their thought has a vocal character. Thinking commonly appears to be accompanied or constituted by silently ‘talking’ to oneself in inner speech. In this paper, we explore the specifically epistemic role of inner speech in conscious reasoning. A plausible position—but one I argue is ultimately wrong—is that inner speech plays asolelyfacilitative role that is exhausted by (i) serving as the vehicle of representation for conscious reasoning, and/or (ii) allowing one to focus on certain types (...) of objects or relations, e.g., causal relations, abstracta, counterfactuals, etc., or to consciously entertain structured propositional contents that it would be hard (or impossible) to focus on or entertain with representations in other (e.g., imagistic) formats. According to this position, inner speech doesn't figure as a justificatory element in our reasoning or as the partial epistemic basis of our conclusions—it merely facilitates reasoning through (i) and/or (ii). In contrast to the view that inner speech is amerefacilitator, I establish that (outside of potentially playing roles (i) and/or (ii)) the language we use itself serves as a crucial source of information in reasoning. In other words, we reason from propositions about the language we use in inner speech as opposed to exclusively reasoning from the semantic contents of the speech. My conclusion follows from how we use language as a cognitive tool to keep track of information, e.g., the contents of premises, lemmas, previous reasoning results, etc., in reasoning. (shrink)