David Botting

Why informal logic? Informal logic is a group of proposals meant to contrast with, replace, and reject formal logic, at least for the analysis and evaluation of everyday arguments. Why reject formal logic? Formal logic is criticized and claimed to be inadequate because of its commitment to the soundness doctrine. In this paper I will examine and try to respond to some of these criticisms. It is not my aim to examine every argument ever given against formal logic; I am limiting myself to those that, as a matter of historical fact, were instrumental in the replacement of formal logic by informal logic and initially established informal logic as a separate discipline. If the criticism of the soundness doctrine is defective, then the move from formal logic to informal logic was not theoretically well-motivated. It is this motivation that I wish to bring into question, rather than the adequacy or inadequacy of formal or informal logic as such. While I will tend to the view that formal logic is as adequate as it is reasonable to expect, the real issue is whether it is inadequate for the reasons that, as a matter of historical fact, were used to motivate its rejection.

In this paper I will argue that most objections to deductive analyses of a priori analogies are incorrect, often involve basic misinterpretations of what the deductive reconstruction of those arguments are saying, and sometimes also betray a confusion about what part of the reasoning corresponds to the analogical inference. In particular, I will be focusing on a raft of objections made by Juthe in [2015] and subject his alternative views to criticism. I will then argue that Juthe does implicitly have a good argument against deductivism: adding further analogues seems to have a cumulative force that they would not have on a deductivist analysis. This is so not only in ordinary analogical arguments but, perhaps surprisingly, with a priori analogical arguments. I will then argue that this does not favor a sui generis view of the analogical argument over inductivist views, and attempt to show that a confirmation-theoretic approach to analogical inference makes the best sense of our intuitions about the strength of analogical arguments.

The lack of a theory of relevance in the current state of the art of informal logic has often been considered regrettable, a gap that must be filled before the Relevance-Sufficiency-Acceptability model can be considered complete. I wish to challenge this view. A theory of relevance is neither desirable nor possible. Informal logic can get by perfectly well, and has been doing so far, with relevance judgments that are by nature unanalysable and intuitive. Criticism of theories of relevance, for example in Woods , is deflated

In this paper I will discuss the rationality of reasoning about the future. There are two things that we might like to know about the future: which hypotheses are true and what will happen next. To put it in philosophical language, I aim to show that there are methods by which inferring to a generalization and inferring to the next instance can be shown to be normative and the method itself shown to be rational, where this is due in part to being based on evidence and in part on a prior rational choice. I will also argue that these two inferences have been confused, being distinct not only conceptually but also in their results and that methods that are adequate for one are not by themselves adequate for the other. A number of debates over method founder on this confusion and do not show what the debaters think they show.

In this paper I want to argue that acts of blame are performed by collectives, and not by any collective but only by collectives that satisfy certain conditions { broadly those that, by collectivizing reason, can be held to be autonomous subjects to which it makes sense to attribute attitudes, including participant reactive attitudes such as resentment. The actors involved must also be related to the collective in particular ways in order to hold and be held responsible, but they need not have the same attitudes as the collective. This implies both that our attributions of moral responsibility to an agent does not depend only on facts about the agent but also on facts about us, and that the reasons for which we hold responsible and by which we justify our moral practices, and which the agent can likewise appeal to in an attempt to avoid being held responsible, depend on the collective involved and its substantive ethical precepts. The answer to whether an agent is responsible, or is an appropriate object of a reactive attitude, is not to be settled purely by philosophical analysis, and even the kind of naturalistic description of the pattern of our reactive attitudes that [22] suggests in \Freedom and Resentment" will only go part of the way { the excuses and exemptions are things we might say in a dialogue where reasons are exchanged, but each collective has some leeway over what substantive reasons count as grounds of an excuse or exemption.

It is a common complaint that the syllogism commits a petitio principii. This is discussed extensively by John Stuart Mill in ‘A System of Logic’ [1882. Eighth Edition, New York: Harper and Brothers] but is much older, being reported in Sextus Empiricus in chapter 17 of the ‘Outlines of Pyrrhonism’ [1933. in R. G. Bury, Works, London and New York: Loeb Classical Library]. Current wisdom has it that Mill gives an account of the syllogism that avoids being a petitio by virtue of construing the universal premise as an inference-rule. I will show that both the problem and the role of inference-rules in its solution have been misunderstood. Inference-rules have very little to do with this problem, and I will argue further that nothing is gained with regard to this problem by the introduction of inference-rules in preference to premises

While “All events have a cause” is a synthetic statement making a factual claim about the world, “All effects have a cause” is analytic. When we take an event as an effect, no inference is required to deduce that it has a cause since this is what it means to be an effect. Some examples often given in the literature as examples of abduction work in the same way through semantic facts that follow from the way our beliefs represent those effects; from this we may deduce not only that it has a cause, but what that cause is

In this paper I will attempt a unified analysis of the various examples of the fallacy of accident given by Aristotle in the Sophistical Refutations. In many cases the examples underdetermine the fallacy and it is not trivial to identify the fallacy committed. To make this identification we have to find some error common to all the examples and to show that this error would still be committed even if those other fallacies that the examples exemplify were not. Aristotle says that there is only one solution “against the argument” as opposed to “against the man”, and it is this solution the paper attempts to find. It is a characteristic mark of my analysis that some arguments that we might normally be inclined to say are fallacious turn out to be valid and that some arguments that we would normally be inclined to say are valid turn out to be fallacious. This is (in part) because what we call validity in modern logic is not the same as the apodicticity that Aristotelian syllogisms require in order to be used in science. The fallacies of accident, uniquely among the fallacies, are failures of apodicticity rather than failures of, in particular, semantic entailment. This makes sense in a tensed and token-based logic such as Aristotle’s. I conclude that the closest analogue to the fallacy of accident that we can point to is a fallacy in modal logic, viz., the fallacy of necessity

Traditionally, logicians construed fallacies as mistakes in inference, as things that looked like good (i.e., deductively valid) arguments but were not. Two fallacies stood out like a sore thumb on this view of fallacies: the fallacy of many questions (because it does not even look like a good argument, or any kind of argument) and the fallacy of petitio principii (because it looks like and is a good argument). The latter is the concern of this paper. One possible response is to say that the tradition is right about the concept of fallacy but wrong about its extension: petitio principii is not a fallacy. If the only proper ways to criticize an argument are to say that it is invalid or that it is unsound, and petitio principii is not criticisable on either of these counts, then calling it a fallacy is tantamount to saying we should prefer invalid or unsound arguments Robinson (Analysis, 31(4): 114 ,1971). I will present a third way to logically criticize arguments and show that fallacious instances of petitio principii are so criticisable while other instances of petitio principii are non-fallacious; hence, this fallacy is not a reductio of the Standard Treatment. It is not my intention in this paper to come out on the side of any of the competing theories—the Standard Treatment, the dialectical theories, and the epistemic theories—as general theories of fallacy. I show only that petitio principii can be handled by something closely resembling the Standard Treatment in so far as that, on entirely logistical principles, there can be made a distinction such that circular arguments form at best a degenerate kind of argument. Circular arguments look like good arguments but are not, not because they are deductively invalid (which they are not) but because they do not deserve to be called arguments at all

Where do the rules of critical discussion get their normative force? What kinds of norms are involved? Unreasonable behaviour in the critical discussion - e.g., continuing to assert the contradictory of a proven standpoint, performing some action pragmatically inconsistent with a proven standpoint, or the same with regard to the starting-points agreed to in the opening stage - is liable to moral sanction. Thus, a moral/ethical norm is involved and the rules must have a moral force. Pragma-dialectics as it stands does not seem to account for this moral force. I will attempt to fill this gap in pragma-dialectical theory.

In this paper I will consider criticisms that have been raised against Broome’s first-order model of practical reasoning by Bratman, Brunero, and Høj. I will modify Broome’s exposition so that it is no longer vulnerable to these objections. The main modification I will make is that I will take the principle Broome dubs the “beliefintention link” to express a pragmatic implicature instead of a material implication, on the basis of which implicatures the process of reasoning Broome describes reaches the conclusion-states Broome desires to reach. This makes a cognitivist account of at least some norms of practical rationality plausible