Reasoning

Reasoning 1.1 Where we begin Interestingly, our study of reasoning begins with the assumption that you already know how to do it. I assume, for example, that some process of reasoning led you to this very page. If a friend were to ask you why you are now reading it, you could give her a reason and probably a pretty good one. I presume your basic reasoning competence in another sense as well. In the following paragraph I will give you reasons why it is a good idea to study reasoning. (After all, I can't make you study it. Whether you do it or not is really up to you.) Notice it would make no sense at all for me to give you reasons for studying reasoning unless I thought that at some basic level you were already competent to recognize good reasons when you see them. So in fact the real question isn't "Why should I study reasoning?" but: • Why should I study reasoning if I already know how to do it? Fortunately, the answer to this is easy: You should study reasoning because, even though you already have some degree of reasoning competence, you can and should improve upon it. All other things being equal, people who reason well are likely to be better off than people who reason poorly, and societies of people who reason well are likely to be better off than societies of people who reason poorly. This is simply because, whether we are good at reasoning or not, most of our significant choices and actions are guided by our reasoning. Hence, the better our reasoning, the more successful these choices and actions are likely to be. As with any claim about the world it's possible to doubt what I have just said. For example, you might suspect that reasoning is highly overrated. You might be inclined to believe that people who rely on reasoning are not as successful as people who, say, just trust their gut instincts. This puts you in an awkward position, however, for presumably you have not arrived at this view by gut instinct, but by a mixture of personal observations and reasoning. Hence, even this view, if it is true, depends on good reasoning skills. 1.2 What reasoning is You've probably noticed that people can be pretty good at an activity without really knowing what they are doing. Good athletes, for example, often display a very poor intellectual grasp of their skills. Socrates, the famous Greek philosopher, made a big deal out of the fact that artists, politicians, mathematicians, etc., have an extraordinarily difficult time defining their subject matter. So, even though I assume you already have some competence in reasoning, I do not assume that you can define it. Let's do that now. Roughly speaking: • Reasoning is the process of providing statements in support of other statements. When I said above that you already know how to reason, what I meant is that you already have a strong intuitive idea of what it is to support a statement with another statement. Now, to make this intuition more precise, we need to define some of the terms that occur within it, and then introduce a couple of other terms as well. Here we go. • • • • A statement is a sentence that is intended to be evaluated in terms of truth and falsity. A supporting statement is called a premise. A supported statement is called a conclusion. Premises that succeed in supporting a conclusion are said to logically imply their conclusion. If you understand the definitions above, then you are in a position to understand the following more technical definition of reasoning. • Reasoning is the process of providing premises that are meant to logically imply a conclusion. 1.3 How we reason We typically initiate the reasoning process when we detect some statement in need of support. Suppose I make the following statement (which, of course, I already have). • People should study reasoning. If you doubt this assertion you might initiate a reasoning process by saying something like: Why do you say that? This is an invitation to reason, and if I accept it, I will try to supply some other statement that would serve as a premise in support of my conclusion that people should study reasoning. In ordinary language, it is typical (but by no means necessary) to indicate that you are reasoning by using the word "because." For example • People should study reasoning because people who study reasoning are better off than people who don't. This, of course, is a perfectly familiar process to you. At this point the only unfamiliar things are the terms we are using to describe this process. It is conventional in logic to reconstruct a person's reasoning by identifying the premises and writing them above the conclusion. So, we would reconstruct this example as follows: Premise: People who study reasoning are better off than people who don't. Conclusion: People should study reasoning. Notice that the word "because" does not occur in the reconstruction. That's because this word is not part of the premise or the conclusion. Rather, it's a word that simply signals that reasoning is going on. (Some other common words with this this function are: hence, thus, therefore and so.)