Valid Arguments "Positive" economists have hoped to put economics on a scientific basis, by confining their attention to issues that can be settled on the basis of observation and evidence. But there are important issues in economics that are not a matter of evidence -- normative issues, the definition of terms and even the subject matter of economics itself. But not only that. We know now that even the classical physical sciences (such as physics and chemistry) are not really that simple. Even in the most scientific of fields, terminology has to be defined. Evidence almost always has to be interpreted. The evidence is what it is, but what does it mean? In economics, these issues cannot be swept under the rug. They have to be discussed.
There is always a temptation to say that all this discussion and argument is just "rhetoric," in the bad sense of that word -- that one person's opinion is as good as that of another. But opinions are no better than the arguments that support them, and some arguments are better, stronger, sounder than others. In order to draw any unprejudiced conclusions in economics -- or in any other field, really -- we have to somehow evaluate arguments, and figure out which are better and which are worse. When we evaluate arguments we are practicing critical reasoning.
Philosophers, psychologists and others have studied critical reasoning and there are some pretty well understood guidelines to better and worse arguments. In my own judgment, one of the best guides to evaluating arguments has come from the philosopher Douglas Walton. These guidelines can be summarized by the phrase reasonable dialog. Reasonable dialog may be defined as an exchange of opinions, questions and answers designed to bring out the reasons for the opinions and to criticize and improve the reasoning of all participants. These objectives define the rules of the conversation.
I have said that economics is a two-hundred year conversation -- but what kind of conversation is it? I believe the economics conversation should be a reasonable dialog, and that, for the most part, that is what it has been. In this text, I will try to present economics in this way: as a reasonable dialog.
Although this is not a philosophy text, we will need to spend a few pages on the evaluation of arguments -- on critical reasoning -- in order to set the stage.
