G. C. Goddu

According to the prevailing sentiment, changing the past is logically impossible. The prevailing sentiment is wrong. In this paper, I argue that the claim that changing the past entails a contradiction ultimately rests upon an empirical assumption, and so the conclusion that changing the past is logically impossible is to be resisted. I then present and discuss a model of time which drops the empirical assumption and coherently models changing the past. Finally, I defend the model, and changing the past, against objections

A world in which time travel into the past occurred would seem like a most strange world. Nicholas Smith, however, in his ‘Bananas Enough for Time Travel’, argues that time travel is not so strange as we think. In particular, he argues against what he views as the main reason time travel worlds seem so strange – the claim that time travel entails unusual numbers of coincidences. I shall argue that Smith's argument for rejecting the claim is inadequate. Hence, the debate over the consequences of the coincidences of time travel cannot be avoided by denying the coincidences themselves

Some philosophers argue that any attempt to model changing the past will either be contradictory or really model avoiding the past. Using Nicholas Smith's (1997) argument as a basis, I formulate a generic version of this Avoidance Argument. I argue that the Avoidance Argument fails because (i) it involves an equivocation of what is meant by ‘bifurcation of the time of an event’ and (ii) resolving the equivocation results in the falsity of at least one of the premises. Hence, the Avoidance Argument will not support the claim that changing the past is logically impossible

The derivation of the generally held Principle of Alternative Possibilities (PAP), roughly ‘you are morally responsible only if you could do otherwise’, from an even more generally held moral principle, K (for Kant), that roughly speaking ‘ought implies can’, has recently been the focus of significant debate. In this paper I shall argue that by focusing on PAP interpreted in terms of commissions alone an alternative derivation of PAP interpreted in terms of omissions is being overlooked. The advantage of the new derivation is that it avoids many of the criticisms directed at the original derivation. Key Words: alternative possibilities • blameworthiness • moral responsibility • omissions.

Suppose you doubt that rationally persuasive arguments can have just premises that are obviously false. But now consider:(X) Grass is red. Some arguments have merely obviously false premises.'Grass is red' is the only premise and is obviously false, so (X) should convince you that there are arguments with merely obviously false premises. On the face of it, there is nothing irrational about being so convinced by (X). But then (X) is a rationally persuasive argument with merely obviously false premises.A cheap trick you say? Not so, say I — a trick yes, but, I shall argue, far from cheap. In ' 'P, Therefore, P' Without Circularity,' Roy Sorensen uses numerous examples like these to suggest, among other things ..

In this paper I argue that the debate over the purported distinction between deductive and inductive arguments can be bypassed because making the distinction is unnecessary for successfully evaluating arguments. I provide a foundation for doing logic that makes no appeal to the distinction and still performs all the relevant tasks required of an analysis of arguments. I also reply to objections to the view that we can dispense with the distinction. Finally, I conclude that the distinction between inductive and deductive arguments is not one of the most important and fundamental ideas in logic, but rather is unnecessary

According to the prevailing sentiment, changing the past is logically impossible. The prevailing sentiment is wrong. In this paper, I argue that the claim that changing the past entails a contradiction ultimately rests upon an empirical assumption, and so the conclusion that changing the past is logically impossible is to be resisted. I then present and discuss a model of time which drops the empirical assumption and coherently models changing the past. Finally, I defend the model, and changing the past, against objections.

In his recent paper, “What a Real Argument is”, Ben Hamby attempts to provide an adequate theoretical account of “real” arguments. In this paper I present and evaluate both Hamby’s motivation for distinguishing “real” from non-“real” arguments and his articulation of the distinction. I argue that neither is adequate to ground a theoretically significant class of “real” arguments, for the articulation fails to pick out a stable proper subclass of all arguments that is simultaneously both theoretically relevant and a proper subclass of all arguments.

In previous work I argued against (i) the likelihood of finding a theoretically sound foundation for the linked/convergent distinction and (ii) the utility of the distinction even if a sound theoretical basis could be found. Here I subject Douglas Walton’s comprehensive discussion of the linked/convergent distinction found in Argument Structure: A Pragmatic Theory to careful scrutiny and argue that at best Walton’s theory remains incomplete and that attempts to fill out the details will run afoul of at least one of the problems adduced above—i.e., result in either a theoretically unsound distinction or a theoretically sound, but unnecessary distinction

Numerous informal logi- cians and argumentation theorists restrict their theorizing to what they call “real” arguments. But is there a clear distinction to be made between “real” and “non-real” arguments? Here I explore four possible accounts of the alleged distinction and argue that none can serve the theoretical uses to which the distinction is most often put. Résumé: Plusieurs logiciens construction formels et théoriciens de l’argument- ation limitent leur non de théories à ce qu’ils appellent des arguments « authentiques ». Mais y-a- t’il une distinction claire entre des arguments« authentiques » et « inau- thentiques » ? Ici j’explore quatre descriptions possibles de cette préten- due distinction et je soutiens qu’- aucune ne répond aux besoins théori- ques auxquels elles sont censées ré- pondre

One popular test for distinguishing linked and convergent argument structures is Robert Yanal's Ordinary Summing Test. Douglas Walton, in his comprehensive survey of possible candidates for the linked/convergent distinction, advocates a particular version of Yanal's test. In a recent article, Alexander Tyaglo proposes to generalize and verifY Yanal's algorithm for convergent arguments, the basis for Yanal's Ordinary Summing Test. In this paper I will argue that Yanal's ordinary summing equation does not demarcate convergence and so his Ordinary Summing Test fails. Hence, despite Walton's recommendation or Tyaglo's generalization, the Ordinary Summing Test should not be used for distinguishing linked argument structures from convergent argument structures

Contextualists with regard to knowledge argue that the truth of the claim 'x knows that P' is contextually dependent. In doing so, they attempt to articulate the nature of the contextual dependence. Since part of making knowledge claims involves the adequate justification of beliefs, I shall explore whether any epistemic contextualist theories can be modified or adapted to provide an account of the context-dependence of justificatory strength for arguments. I shall conclude that the prospects are not promising.

A world in which time travel into the past occurred would seem like a most strange world. Nicholas Smith, however, in his ‘Bananas Enough for Time Travel’, argues that time travel is not so strange as we think. In particular, he argues against what he views as the main reason time travel worlds seem so strange – the claim that time travel entails unusual numbers of coincidences. I shall argue that Smith's argument for rejecting the claim is inadequate. Hence, the debate over the consequences of the coincidences of time travel cannot be avoided by denying the coincidences themselves.

An enthymeme is often defined as an argument with a missing component or an argument with an unexpressed component. Roy Sorensen, in “Are Enthymemes Arguments?”, argues against the possibility of enthymemes being arguments at all, but he assumes that arguments are abstract objects. I shall present and explore some more metaphysically neutral arguments against enthymemes as arguments and ultimately conclude that while not conclusive, the most viable option is Sorensen’s—enthymemes are not arguments.

While there has been in depth discussion of many particular argumentation schemes, some lament that there is little to no theory underpinning the notion of an argumentation scheme. Here I shall argue against the utility of argument schemes, at least as a fundamental part of a complete theory of arguments. I shall also present and defend a minimalist theory of their nature—a scheme is just a set of proposition expressions and propositional functions. While simple, the theory contravenes several typical desiderata of argumentation schemes such as aiding in the identification of enthymemes and keeping arguments constrained to a manageable taxonomy. So much the worse for the desiderata. Instead, I shall recommend focusing less on schemes and more on the component propositional functions.