Arguing Well

John Shand

• Publisher: Routledge
• Year: 2002
• eBook ISBN: 9781134706129
• Topic: Philosophy
• Subtopic: Philosophy History & Theory

Arguing Well is a lucid introduction to the nature of good reasoning, how to test and construct successful arguments. It assumes no prior knowledge of logic or philosophy. The book includes an introduction to basic symbolic logic. Arguing Well introduces and explains: * The nature and importance of arguments * What to look for in deciding whether arguments succeed or fail * How to construct good arguments * How to make it more certain that we reason when we should The book is ideal for any student embarking on academic study where presenting arguments are what matters most; in fact, for all people who want to understand the nature and importance of good reasoning and awaken their ability to argue well.

1
RATIONALE

1.1 The overall purpose of this book is to present the basic tools and principles of good reasoning in arguments, and to suggest how one might acquire habitual mechanisms to overcome causal forces that would undermine reasoning. It is meant as a precursor to, and preparation for, any course that involves the assessment and construction of arguments. But it is also hoped that the book contains ideas that the reader will find interesting in themselves and be able to apply generally in the conduct of his life.

1.2 It is made clear in the book what the value of reasoning is, and that the nature of reason as such is logically distinct from the psychological processes involved in acquiring beliefs. Using reason, that is the act of reasoning, is a psychological process, and is also distinct from reason as such. Reasoning is one way of acquiring beliefs, indeed a way that has merits that are here defended, but good reasoning is not defined by its being a route to belief. A process of reasoning may or may not lead to a belief at the end of it. Reasoning is not, insofar as it is good or bad, concerned with the outcome of someone's having a belief, but with whether that belief is justified. A sharp distinction is made here between logic and rhetoric (in the broad sense): between processes leading to our coming to conclusions (rhetoric) and our being justified in holding those conclusions on the basis of argument (logic). Reasoning may as a matter of fact convince us of a proposition, but we can be presented with a piece of reasoning that is perfectly sound whether this is the outcome or not.

The aim of the book is twofold:

1. It will enable the reader to assess writings or assess speech more actively, when the purpose of that assessment is the quality of arguments; and it will enable the reader to construct better arguments more consciously when writing and speaking, when it is the quality of arguments that is the primary concern.
2. It will enable the reader to better counter those forces that would tend to cause the reader to reason badly or not at all in circumstances where they should be reasoning.

1.3 There are theoretical arguments behind the book, which are partly contentious, but a consideration of these will I hope deepen readers' appreciation of the notion of reason and reasoning. The theoretical contention of the author is that the notion of good reasoning can be reduced to a certain basic idea. That idea is deductive soundness as defined by the notions of validity and truth. This makes the distinction between good and bad reasoning decisively, because if anything counts as good reasoning then deductive reasoning does. The aim here is not so much to make this theoretical point as to give readers a useful tool with which to assess the merits of arguments that they encounter in their reading or in speech, and with which to construct arguments of their own.

The view here is essentially a reductionist one with regard to good reasoning and fallacies. Good reasoning can be reduced to a single notion, that of deductive soundness: (a) the premises must be true and (b) the argument valid so that the conclusion follows from the premises, in that to assert the premises and deny the conclusion would involve a contradiction, that is, would be inconsistent. It is from (a) and (b) alone that an argument giving one a reason to accept a conclusion as true is ultimately derived. Included in the analysis of validity is that it is a matter of form, and that one should not be distracted by irrelevant content in assessing validity. Individual arguments are valid because they are instances of valid forms of argument: valid argument-forms. In this way, it is hoped, the notion of good reasoning can be applied to any situation irrespective of subject matter.

1.4 What are often referred to as ‘fallacies’ are not significant because they are errors in formal reasoning — such errors are usually so obvious as to be hardly worth pointing out — but rather because they are psychological rhetorical tricks designed to fool people into thinking they have been presented with a good argument when they have not, in order to convince them of a conclusion. This may be because there is no good argument for the conclusion. To avoid fallacies it is only required that one stick by the principles of good reasoning — the conclusion really follows from the true premises — in this way all fallacies collapse together. The distinctive feature of what are often called fallacies is not their formal failure to abide by the rules of deductive soundness — although they may do this too — but rather their effectiveness as psychological tricks whereby someone thinks they have been presented with a good argument when they have not. The only true fallacy in the end is the one where there has been a failure to argue with deductive soundness: true premises and a valid argument.

1.5 In addition it is a theoretical contention of this book that the only thing that can give one a good reason for a belief or an action is that there is a sound argument for it, one whereby the conclusion is the belief in question or the conclusion is a prescription that the action in question should occur. Neither beliefs nor facts about the world can in themselves give one a reason to believe or do anything. Either may cause one to have other beliefs or act, but that is distinct from having a reason. That this is not obvious is obscured by the banality of latent and tacit arguments that give the false impression that we move directly from belief or fact to a conclusion. However, if one has a reason at all to believe or act, there must be a good argument — an argument that will most likely connect other beliefs or facts to the final belief or act in a structure of normative justification. Facts and beliefs, as with causal processes, are in themselves logically inert; they have no bearing alone as to whether one has reasons. Only when linked in an argument do they have rational force.

For example, it might be said that I have a reason not to climb down a cliff if I believe it to be crumbly or I have a reason because it is in fact crumbly — but neither belief nor fact of itself gives me a reason. It only seems to because we tacitly presuppose a good argument (or at least an argument), something along the following rough lines perhaps.

• I do not want to hurt myself and die
• Crumbly rocks on cliffs like these if climbed down are a likely way to hurt oneself or die
• These rocks are crumbly or I believe them to be so
• 
• Therefore, I should not climb down the cliff

This contention applies even to cases where simple perception is involved. One might think that I have a reason for believing there is a glass of water in front of me if I can see it. But built into ‘see’ here is an argument, familiar to philosophers if not to others, linking my having the experience of seeing a glass of water with my having a reason for believing that there is a glass of water. Indeed it is a matter of philosophical debate just how strong this argument can be — but however that turns out, an argument is essential for my being justified, my having a reason. In short there is an argument that seeing the glass in given circumstances is a good reason for believing there is a glass to be seen. My merely seeing the glass of itself implies nothing. It is in fact not hard to think of cases where we might be deluded. Again, whatever one thinks of that, one is always involved in an argument, and one is tacitly saying there is a good argument when contending that a certain belief is true or one has a reason to act in a certain way. It is just that most of the time, through familiarity, we do not notice that such latent arguments are tacitly assumed.

1.6 An important distinction is made between the objective failure (and success) of arguments and the person-directed failure (and success) of arguments. A successful argument gives a reason for its conclusion being true. In the objective sense an argument is a success if it is an instance of a valid argument-form, where contradiction would be involved in asserting the premises and denying the conclusion, and if it involves only true premises. If someone is presented with such an argument, he has been given a good reason for accepting the conclusion as true in the objective sense whether he (or anyone else) does so or not. However, even if someone is presented with such an argument it may not give him a good reason for accepting the conclusion as true. Thus an argument may fail in the person-directed sense because the person to whom it is directed may be unable to accept the premises as true or see that it is valid. The argument may be successful in the objective sense — have true premises and be valid — yet fail in the person-directed sense because a person cannot accept the premises or that it is valid. Note the obverse is not the case: an argument cannot be a success in the person-directed sense and yet fail in the objective sense. If an argument fails in the objective sense — either because it contains false premises or is invalid, or both — it cannot give anyone a good reason for the truth of the conclusion, that is a reason in the person-directed sense, because it does not give a reason at all, whatever people viewing the argument may think about it and however acceptable they may find it. A person may think an argument gives him a reason to accept a conclusion as true, but if it is not a good argument in the objective sense then he is mistaken.

It should be noted that the objective and person-directed distinction is not a matter of psychology but a purely conceptual one. In the person-directed sense arguments fail, not because they fail to convince as a matter of psychological fact, but because, in the sense of a person either not knowing whether the premises are true, or being unable to see that the conclusion follows from the premises, that person has not been given a reason to believe the conclusion is true — although in the objective sense he may have been given such a reason. In such cases, for an argument to be a person-directed success I may need elucidation and perhaps further justification given to the premises — the premises that I find unacceptable will form the conclusion of another argument that I can accept — and in that way I can accept the conclusion of the original argument. It is not a matter of convincing me but of giving me a justification. All that is needed for the objective success of an argument is that its premises be true and it be valid, in which case the conclusion is true, whether anyone can see these things or not. Indeed it might be the case that no one can know if an argument has premises that are true (we might have no access to information that would confirm the premises), or if the argument is valid (it might be so complex as to be beyond our comprehension), for practical reasons or even in principle, but for all that it could be a good argument in the objective sense.

1.7 Let me give an example of how the objective and persondirected distinction works in practice. It is, in the person-directed sense, as far as being presented with a good argument is concerned, no use for an oncologist to present to me an argument that I have cancer on the basis of premises that are unacceptable to me either because I do not know if they are true or because they are beyond my understanding. Similarly, it is, in the person-directed sense, as far as being presented with a good argument is concerned, no use for an oncologist to present to me an argument that I have cancer whose validity I cannot see, perhaps because it is beyond my comprehension. If I am to be given a good reason for accepting the conclusion as true on the basis of an argument (as opposed to accepting the conclusion by trusting that the oncologist has a good argument and knows his job), then I must be given an argument that I can see to be valid and that has premises that I can accept, even if the original argument was perfectly good in the objective sense in both being valid and having true premises. I must be given a good argument in the person-directed sense. If my doctor tells me I have cancer, and I do not understand the argument or know whether the premises are true, so I cannot see rationally how he comes to his conclusion, then to give me a good argument the doctor needs to argue in some simpler way that I do understand and can accept. Obviously there are limits to how simple and basic arguments can get.

Of course I might just accept the oncologist's conclusion anyway; but one should do this not on trust (whatever that means) or because he is a ‘specialist’ as such, but because we think he is arguing validly from true premises whether I can see it or not. If he has such an argument, then the conclusion that I have cancer is true. Of course the conclusion may be true anyway, but if it does not follow from true premises validly, then there is no argument for its being true. The appeal to the authority of a cancer specialist as to whether I have cancer might look in a sense like a good argument in itself — but this is an illusion except insofar as by ‘cancer specialist’ we mean someone much more able than most to marshal good arguments in the objective sense in the field of cancer. The real question is not what a person is called, or what authority he is supposed to have, but whether he is good at constructing good arguments: validly deducing conclusions from true premises.

1.8 It is sometimes argued that deductive reasoning alone is too restrictive to characterise what is permissible as good reasoning: that there are other non-deductive modes of reasoning that are perfectly legitimate, depending on the circumstances. This includes supposed arguments that are based on, for example, authority, emotion, popular opinion and of course induction, that are said to be legitimate in certain circumstances. This I believe is a mistake. In each case the putatively legitimate modes of nondeductive reasoning are only so because they are tacitly dependent on the basic notion of deduction. The confusion arises because this is not seen, but instead the legitimacy of the argument is ascribed to the surface circumstances and the fact that one may come up with true beliefs. But coming up with true beliefs is not enough to show that the method by which one does so constitutes a good argument, or indeed an argument at all — for this there needs to be given a reason for the belief even if it is true, and for that it must come as the conclusion of a piece of sound deduction. In all cases either there is an argument where by starting from true premises and moving with deductive validity one could derive the conclusion, or there is not — and if there is not, despite the appearance, such as appealing to an authority, one does not have a reason for accepting the conclusion as true.

There is a belief that there must be legitimate forms of reasoning weaker than deduction if we are to do justice to our actual reasoning. But this confuses the nature of good reasoning — which is deductive — with our ability to know the truth of the premises required to turn these weaker forms into pieces of sound deduction. Often we have to be satisfied with reasoning that is less than deductively perfect not because the less perfect reasoning is legitimate in itself, but because we are unable to know the truth of premises that would turn it into a deductive piece of reasoning. So we leave them out. But if it is justifiable for us to believe the conclusion true at all on the basis of an argument, such premises have to be true and the argument valid.

1.9 One common source of legitimate reasoning other than deduction is said to be induction. Inductive arguments are such that their conclusions go beyond the content of their premises. One might argue from the premise that ‘All observed swans are white’ to the conclusion that ‘All swans are white’. Deductively this is fallacious in that the premises could be true and the conclusion could be false without any contradiction being involved — in fact the conclusion is false. To see induction itself as a legitimate form of reasoning is I believe an error. It is legitimate only insofar as it is seen as a form of deductive reasoning with suppressed premises. Indeed, all non-deductive reasoning should be looked upon as enthymemes: that is, deductive arguments, if they are arguments at all, with missing premises. The question of whether premises can be established as true is an entirely separate matter from what constitutes good reasoning. If we cannot establish premises as true in order to turn an argument into a deductively sound one, then so much the worse for that argument; it should not lead us to concoct spurious legitimation for the supposed ‘validity’ of forms of reasoning, such as induction, which are weaker than sound deduction. The premises required to turn the weaker forms into sound deduction may just be true, in which case their inclusion gives a reason for the conclusion being true whether we can know those premises are true or not. Our inability to establish them as true should not lead us to proffer anything other than deductive soundness as reasoning proper.

What might turn an inductive argument into a deductive one would be the addition, in any case of inductive reasoning, of a Uniformity of Nature Principle. Indeed, without such a premise it is difficult to see how anything very much follows from the premises usually found in inductive reasoning. The Uniformity of Nature Principle will say something like: there are laws of nature, and they hold universally in both space and time. Take the following inductive argument:

• All observed free rocks near the surface of the earth fall towards the centre of the earth
• 
• Therefore, this free rock near the surface of the e...

Table of contents

• COVER PAGE
• TITLE PAGE
• COPYRIGHT PAGE
• PREFACE
• INTRODUCTION
• 1: RATIONALE
• 2: ARGUMENTS
• 3: HOW ARGUMENTS FAIL
• 4: DEFINITIONS
• 5: BASIC SYMBOLIC LOGIC
• 6: UNDERSTANDING REASON IS NOT ENOUGH
• FURTHER READING