2.2 Reasoning

Topic 3: Critical Thinking
Topic 4: Knowledge
Topic 5: Argument
Topic 6: Reason
Topic 7: Objection
Topic 8: Basis

Topic 3: Critical Thinking

Critical thinking, in a nutshell, is the art of being right. People think in many different ways. Some of those ways of thinking are more reliable than others, in the sense that they are more effective in helping people determine which propositions are true and which are false.

Critical thinking, by definition, is thinking in those more reliable or effective ways. It is applying the thinking techniques that work best in helping you arrive at knowledge rather than error.

Critical thinking is the active, skillful deployment of those general principles and procedures of thinking which are most conducive to truth or accuracy in judgment.

But what are those general principles and procedures? It has taken many centuries to answer this question, and we still have not figured it out completely. However, we do under- stand the basics pretty well.

The foundation of critical thinking is understanding how claims are supported or op- posed by evidence, i.e., the information that is relevant to whether the claim is true or false. Any particular piece of evidence can be cast in the form of a reason for, or objection to, some claim.

So at the most basic level, the general principles and procedures you need to be a critical thinker are the ones governing reasoning and argument. In other words, they are the concepts, rules, techniques, strategies, tips and procedures described in these topics.

In understanding what critical thinking is, it might help to contrast it with some forms of ‘uncritical’ thinking:

• Accepting things purely on faith.
• Thinking that any person’s beliefs, including your own, are ‘true for them’ and cannot be mistaken or criticized.
• Thinking that your beliefs or worldview somehow require your allegiance. On the contrary: your beliefs should serve you, and they will do that best if they are true.
• Being too lazy to seek evidence or challenge beliefs.

The nature of the critical thinker was described well by Francis Bacon in the 17th century:

‘For myself, I found that I was fitted for nothing so well as for the study of Truth; as having a mind nimble and versatile enough to catch the resemblances of things (which is the chief point), and at the same time steady enough to fix and distinguish their subtler differences; as being gifted by nature with desire to seek, patience to doubt, fondness to meditate, slowness to assert, readiness to consider, carefulness to dispose and set in order; and as being a man that neither affects what is new nor admires what is old, and that hates every kind of imposture. So I thought my nature had a kind of familiarity and relationship with Truth’. – from The Advancement of Learning.

See also: Topic Proposition

Topic 4: Knowledge

What is knowledge? This question is answered in different ways in different contexts, but for our purposes, the classical philosophical definition is the most appropriate:

Knowledge is justified true belief.

That is, you genuinely know something when you believe it, you are justified in believing it, and it is actually true.

Suppose, for example, you believe that the No.19 tram goes along Royal Parade in Melbourne, Australia. If the No.19 tram does not go along Royal Parade, you do not know that it does; you merely believe that it does, and you are mistaken.

If the No.19 tram does go along Royal Parade, you have a true belief. But suppose you only believe it because you just took a wild, very lucky guess. Then you still do not know that it goes along Royal Parade; you merely have a belief which, as it happens, is in fact true. You need some proper basis or justification for your belief.

Epistemology

In fact, the real story is considerably more complicated (1). The study of knowledge – of what it is to know something – is known as epistemology:

Epistemology is the philosophical study of the nature of knowledge.

Epistemologists ask questions such as:

• What is knowledge, anyway?
• Under what conditions can somebody be said to know something?
• What sorts of things do we know?
• What are the best procedures or methods for obtaining knowledge?
• Do we really know anything at all?

If you are interested, you can study these topics in detail in one of the various upper-level philosophy subjects in this field.

• See also: Topic Critical Thinking
• Knowledge: in the Tutorial Reasoning for Knowledge

Topic 5: Argument

When you hear the word ‘argument’, your first thought might be of people disagreeing, even yelling at each other – or worse!

Logicians (that is, people who study reasoning) tend to use the word rather differently. Roughly, an argument in this sense is what people provide when they try to show that a certain claim is true – or alternatively, that a certain claim is false. For our purposes (2),

An argument is an integrated set of reasons or objections bearing upon some claim.

We use the term contention for a claim upon which an argument bears.

What does it mean to ‘bear on’ a contention? It just means that the argument has been presented by somebody as relevant to whether the contention is true or not.

Reasons and objections are themselves sets of claims, known as premises. So it is possible to think of an argument as a structured set of claims bearing upon a contention.

Figure 2.6 An example of a complex argument

Simple and Complex
In the simplest case, an argument would be just a single reason, or a single objection. We refer to these as simple arguments. Complex arguments are made up of multiple reasons or objections connected in an integrated structure.

Good Arguments and Bad Ones
Not all arguments are good arguments! Good arguments are the ones that give us a solid basis for believing or disbelieving the contention. Bad arguments are ones that do not. Evaluation is the process by which we judge whether an argument is good or bad.

What are Arguments for?
Arguments are attempts to trace the web of implications among our ideas – that is, how accepting some claims should affect our acceptance of others. Thus a simple argument with one reason says, roughly, that if you believe the premises, you had better also believe the contention.

Arguments are used in a number of different ways, including:

• To justify. Suppose I want to show that my belief in a certain claim is appropriate. I can use arguments to show that the claim is true because it is supported by other claims which are true. In other words, I can use arguments to justify my claim.
• To persuade. Arguments can be used in the attempt to persuade another person to believe (or reject) a claim. This activity is argumentation.
• To infer. Arguments can be used to extend our knowledge by showing that certain claims we already believe provide evidence for another claim. This process of drawing out the implications of what we know by chains of arguments is inference.

Arguments and Argumentation
The word ‘argument’ is often used to refer to a disputatious activity, as in ‘There was an argument going on about who should inherit the old man’s Bugatti.’ Argument as an activity naturally involves arguments in the sense of sets of reasons and objections. To distinguish these subtly different notions, we refer to the activity of argument as argumentation.

See also: Topics Reason and Evaluating Reasons

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(2) Our definitions here differ slightly from what you might find in standard logic textbooks. Logicians typically refer to the claim, upon which an argument bears, as the conclusion, and define an argument as a set of claims, one of which is a conclusion and the others of which provide evidence for that conclusion. We believe, of course, that the usage recommended here is more natural and useful.

Topic 6: Reason

The English word ‘reason’ is used in many different ways; when used as a noun, it can refer to a number of different kinds of things. However, when studying reasoning and argument, we are mostly interested in just one of these kinds of reasons. In this sense,

A reason is a group of claims, known as premises, treated as jointlyproviding evidence that another claim is true.

Reasons of this kind are logical or evidential reasons. These contrast with another large and important category of reasons, the explanatory reasons or explanations.

Note that although a reason is a group of claims working together, often in ordinary dis- course only one of those claims is actually presented (see enthymeme). In such situations people often refer to that one claim as the reason, though strictly speaking it is only part of the full reason.

Reasons and Evidence
What is ‘providing evidence that another claim is true’? The basic idea is that, if the reason is any good at all, the premises make it more likely that the contention is true. We talk about this special relationship in a variety of ways:

• A reason supports the contention.
• A reason lends weight to the contention.
• A reason lends credence to the contention.
• A reason provides a basis for believing the contention.
• A reason proves the contention (if it is very good).
• You can infer the contention from the reason.

Figure 2.7

Good Reasons and Bad Reasons
What makes a group of claims a reason? Answer: being treated as evidence relating to that claim. To be a reason is to be sincerely put forward or accepted as a reason by somebody.

This has a very important consequence: reasons can be bad. The person advancing the reason probably thought it was pretty good, but may have been confused about that.

So when is a reason a good one? There are two main dimensions to the quality of a reason. To be good, a reason should be

• Well-formed. The reason must be built correctly. The premises must relate to the conclusion and to each other in the right kind of way. For more on this, see below.
• Strong. The reason must be such that make the conclusion substantially more likely to be true than it would be in the absence of that reason.

These dimensions are not independent of each other. In order to have strength, reasons must be well-formed. Still, it is quite useful to think of reasons from these two distinct perspectives.

See also: Topic Evaluating Reasons

Topic 7: Objection

An objection is a special kind of reason – one that provides evidence against a claim.

An objection is a group of claims, known as premises, treated as jointly providing evidence that another claim is false.

We talk about the special relationship between an objection and the other claim in a variety of ways:

• An objection provides evidence against a claim, i.e., evidence that it is false.
• An objection opposes a claim.
• An objection undermines a contention.

Objections and Reasons
Since objections provide evidence that a claim is false, you can often treat an objection as a reason to think that the opposite of the claim is true. In other words, an objection to claim C is a positive reason for ‘It is not the case that C’ (technically known as the negation of C).

Generally, it is easier to deal with reasons rather than objections, so we prefer the ‘reason’ form to the ‘objection’ form. In many cases, however, it is important to use the ‘objection’ form. For example, in critical evaluation we are trying to represent and evaluate reasoning presented by somebody else. If that person presented their reasoning in the form of an objection, we should evaluate it as such.

Objections to Reasons
Often a person appears to be objecting not to a claim directly, but to a reason. The objection says, in effect, ‘that reason is no good.’

Upon closer inspection, such an objection may take one of two forms. First, it may be providing evidence against the truth of the premise (or one of the premises). In this case it can be described as a ‘premise objection’ – an objection to a premise. Second, it may be providing evidence that the premise does not support the main contention. In this case, it is known as an inference objection. Every inference objection can, however, be shown to be an objection to an as-yet-unstated premise.

Rebuttals – Objections to Objections
Just as there can be objections to reasons, there can be objections to objections, known as rebuttals. A rebuttal provides evidence that the original objection is no good. As with objections to reasons, there are two kinds: premise rebuttals, and inference rebuttals.

Figure 2.8 Premise Rebuttal and Inference Rebuttal

Objections versus (mere) Denials
A proper objection provides evidence against a claim; it is not just rejecting it. For example, if you say ‘Money is the path to happiness,’ and I say ‘That’s absurd!’ I have not made an objection in the current sense. I have merely denied the truth of your claim.

To raise an objection I must provide some further information which might rationally persuade you that your claim is false. For example, I could say ‘There is considerable statistical evidence that beyond a certain minimum level, wealthier people are not happier than less wealthy people.’

Mere denials can be quite blatant, but people often disguise them. They try to act as if they have provided a genuine reason to reject the contention, but when you look carefully, they have not provided any distinct evidence.

See also: Topics Reason and Inference Objection

Topic 8: Basis

Often it is reasonable to accept a claim as true even in the absence of any arguments for or against it. For example, suppose you are in a restaurant, and the waiter says ‘I’m sorry, there is no more barramundi tonight.’ Usually it would make sense to take the waiter’s word for it, and accept that you did, in fact, miss out on the barramundi. Put another way, your basis for accepting that the barramundi is all gone is simply the waiter’s assertion to that effect.

Notice that the waiter’s assertion is not an argument. In saying that ‘there is no more barramundi tonight’ the waiter has not provided any evidence that there is no more barramundi; he has simply said that there is none.

Figure 2.9

More generally, assertion by another person is one of many kinds of non-argumentative bases you might have for accepting a claim.

A basis is any source of rational support for a claim other than a reason or objection.

Other bases include expert opinion, personal experience, common belief, example, publication, and by definition.

Evaluating Bases
Although bases are not arguments, they can be evaluated in terms of the extent to which they provide rational support for a claim. For example we can evaluate assertions as bases for the asserted proposition. We might accept that there is no more barramundi because the waiter said so, but no thoughtful person would accept that global warming is uncertain because an oil industry lobbyist said so.

We normally evaluate arguments in terms of strength. We could, similarly, talk of bases as being more or less strong, but this would be muddying the waters, since bases and arguments are somewhat different in nature. A suitable alternative is to evaluate bases as having degrees of solidity – solid, shaky, worthless etc.

Critical Questions
When judging the solidity of a basis, we should use criteria appropriate to that basis. For example, the solidity of an assertion as a basis turns on issues such as: Is the person making the assertion reliable? Is he being sincere? Does he know what he is talking about?

Here a map with specific critical questions you should ask yourself to evaluate the solidity of different bases:

Figure 2.10 Critical Questions for Bases. Click here for the pdf.

Converting Bases into Arguments
It is always possible to convert a basis into an argument, by articulating it explicitly in the form of a claim or claims. Thus I can accept that there is no more barramundi on the basis that the waiter said so; or, I can construct for myself an argument such as the one below. Notice that the criteria for evaluation of the basis make an appearance in the premises of the argument. Figure 2.11

Regresses and Terminals
Bases address a profound issue in the evaluation of arguments. We often hear the supposed principle that a critical thinker only ever accepts claims on the basis of good arguments. However, this cannot always be true, for it creates what philosophers call an infinite regress. Arguments are made up of premises, which must be accepted if the arguments are to provide any support. Hence, if we subscribe to the principle, we must look at the arguments for those premises, and so on forever.

It appears that the critical thinker would never get to accept anything, because she would never complete the infinite task of investigating all the arguments. The regress can only be broken if there are situations in which we can reasonably accept claims as true without investigating further arguments. This is where bases come in; they allow us, provisionally at least, to rationally accept claims in the absence of explicit arguments. They are stopping points or terminals in the process of determining whether a claim has rational support.