To many people, a first question about logic might well be: why is it part of philosophy rather than mathematics? Let’s begin this class with a few comments about the nature of philosophy, and the central role of logic in it.
So, what’s philosophy anyway? Most people in the USA in an Introduction to Logic class will not have had any previous courses in philosophy. This is largely because in the public school systems in the USA, philosophy is not taught seriously. It may not even be taught at all, or students might get no more than the names of a few representatives of the philosophical tradition, like Socrates, Plato, and Aristotle.
There is perhaps no better sign of how poorly our schools prepare our students for real life and responsible citizenship than the fact that they avoid philosophy in the high school curriculum. To teach philosophy is to invite people to take up a critical and sceptical stance on what they have learned to take for granted as true and obvious. If you consider it apart from the division into interests like metaphysics and epistemology, you might say that the fundamental questions of philosophy in general are a) what do you mean by that? and b) why should we believe it?
In the above, I am not criticizing the schools; I am criticizing the society that wants its schools to be this way. Not all that many people seem to spontaneously enjoy the atmosphere of critical reflection upon their basic assumptions. Let me offer a personal story.
After I had begun my first teaching job, my father finally asked me what it was that I did. To try to explain to him what philosophy was, I recounted the situation Socrates encounters in the dialogue known as “Euthyphro,” the situation that sets off the discussion of the dialogue. The situation is the following (set, of course, in ancient Athens): Euthyphro’s father found that one of his servants had killed another man, a slave. He tied up this servant and left him in a ditch, exposed to the elements, and sent another servant to the city for advice. By the time advice came, the servant in the ditch had died. Euthyphro considers his father responsible for the death, he considers him a murderer. His father, on the other hand, says that’s ridiculous, because the servant was himself a murderer, and that all he did was tie him up, not kill him. In the context of ancient Athens, furthermore, it is not just lip service to say that children must obey and not question their parents. That old Commandment about “honor thy father and thy mother” is part and parcel of a code of ethics that was taken totally seriously. So when Euthyphro decides to bring his father to trial as a murderer, on the grounds that his father’s actions led to the death of a man who was himself a killer, his family is angry with him and accuses him of acting impiously. By “impiously” they mean something like “against the will of the gods.” That’s the background.
Now, in the dialogue, Socrates encounters Euthyphro near by the law courts and they talk about why they are there; Euthyphro provides this background story, and Socrates says, basically, “Wow, you must be quite a wise and accomplished man to be confident that what you are doing is really the right course of action. After all, it flies in the face of our ethical code that says parents are the superiors of their children (even their adult children).” And Euthyphro agrees that he is wise and accomplished. So Socrates begins asking him to share his insight, his knowledge of the nature of what is pious in particular. That’s what the dialogue is about. The best answer Euthyphro can come up with to define “the pious” or “piety” is that the pious is what is loved by all the gods. At one point, a decisive question is asked by Socrates:
“So is the pious pious because it is loved by the gods, or is it loved by the gods because it is pious?”
Now, what does this mean?
In updated language, it means: Is something called “good” because God says it’s good, or does God say it is good because it is good?
When I’d showed this to my father, in order to tell him that that was the beginning of moral philosophy, i.e., of thinking philosophically about the concepts that make up our framework for judging about right and wrong, he responded:
“Oh, that’s a terrible thing to ask a person.”
That was all he needed, more than enough, to know that he didn’t want to have anything to do with philosophy. That’s the kind of thinking that makes your head hurt, or that makes you feel insecure about your certainties, or makes you doubt yourself.
It’s people like my father–and I think in this regard he’s quite typical of how most people in most parts of the world throughout most of history have been–who are behind the fact that our public schools don’t teach philosophy, don’t seriously teach critical reasoning. The ability and desire to thoughtfully and carefully critique what we take for granted is a challenge to the confidence that they want to convey to the younger generation, a challenge to the certainty that they want the next generation to have, about the values and views that they are being raised in.
Philosophy as it has been understood and developed in Western civilization, is such a challenge, it is the unapologetic invitation to critically examine the adequacy of the beliefs and values that we live by and take for granted. And to someone who is a philosopher, this way of living –Socrates called it “the examined life”– is of more value than anything. Socrates said to the court that tried him and ordered his execution, “the unexamined life is not worth living.”
I hope that conveys something about what philosophy is. It’s an attitude firstly. The attitude that says: things had better make sense, or at least make better sense than they seem to make. What justifies the belief in this or that value, this or that way of doing things? Why should I believe that that is true?
Philosophy is a sort of obsession with truth, i.e., with the justification of what we believe. And a central and constant element of that is a preoccupation with clarity. That’s why I said earlier that the two most basic questions of philosophy were: a) what do you mean by that?, and b) why should we believe you?
OK, so that’s a first and general notion of philosophy as a field. But just what is out there in the field of philosophy?
Typically we say the kinds of things about which we ask these two basic questions concern:
1. What there is, and what it is like. For instance: is the mind a separate thing from the body? Is the mind the same thing as the soul? What happens to us when we die? In philosophy, these kinds of questions are called “metaphysical.” They have to do with the meaning of “being,” with the question of what is real, and with the question of the nature of what is real.
2. What knowledge is, and how it differs from other things like ignorance, belief or opinion. If you believe something is true, and you happen to be right by luck, why wouldn’t it be correct to call that “knowledge”? What is the relationship of the mind to what we call “true” or “truth”? In philosophy, these kinds of questions are called “epistemological.”
3. What right and wrong are, and how we ought to live. Is what is right right because God decrees it, or does he decree it because he’s smart and he can tell that it is right all by itself? Do “human rights” really exist? Is it wrong to kill in all circumstances? In philosophy, these kinds of questions are called “ethical” or “moral.”
4. What good reasoning is, and how we can tell when reasoning is going “off track.”
This number 4 is Logic, the study of reasoning. This is what lets us acquire some confidence about what constitutes good reasoning (and why it does), and what constitutes bad or unreliable reasoning (and why). You can see that number 4 is quite important, because it doesn’t take much to realize that the only way to get answers to the kinds of questions raised in metaphysics, epistemology and ethics is by reasoning. There are no “scientific” answers here. You can’t run tests to see which view is the correct one. These questions are all more “basic” than the kinds of things that scientific inquiries can get at.
You might be able to see now that it doesn’t matter whether you are reasoning about the nature of reality, the nature of knowledge, the nature of right and wrong, about why peanut butter is sticky, about where you left your shoes, or about why all triangles have 180 degrees–in any of these cases, there is reasoning better and there is reasoning worse. Reasoning and mathematics are not identical; mathematics is reasoning in which numbers and numerical relations are the objects of interest. That presupposes logic, i.e., it presupposes answers to the questions: what is good reasoning? what is validity? what is entailment?, etc.
Logic as a body of knowledge comes from reasoning about reasoning, and judging the differences between better and worse in –as this course will show–a variety of domains: from everyday contexts using ordinary language to techniques of representation and judgment. Much of it involves getting clarity about the meaning of the words we use to talk about meaning and about reasoning, and much of it involves practice at applying techniques to examples. As a result, even though from one day to the next the concepts we’ll talk about are not very difficult to grasp, there is a challenge in keeping all the distinctions clear and staying on top of the material as it builds. The only way to meet those challenges is to get regular practice and feedback, which is why homework will be assigned daily, and why every effort will be made to engage you individually in the course material.