Inductive Argument Forms

Introduction -- The amazing scope of inductive evidence

We will not find as simple a way of talking about inductive form as we did with Deductive Argument Forms. But before we tackle that problem, let's remind ourselves, in a detailed way, about the scope of inductive reasoning. Remember that the Principle of Induction identifies the assumption that nature is uniform and, perhaps further to the point, that this uniformity can be studied in a way that helps us theorize about all kinds of things, from the nature of a dungbeetle to the explanation for music and reason in human beings. In other words, we can have not only biology, physics, and chemistry, but also psychology, sociology, and anthropology. While the patterns we observe in different disciplines depend upon different empirical methods, at root, the process of induction drives a good deal of theory building across these disciplines. Let's call this "induction in the sciences".

Then there's ordinary induction -- the kind of inference based on a claim about a pattern in your experience. You rely implicit on numerous regularities in your experience. Our confidence in the rising of the sun, the reliability of building materials (especially of the floor and building that are probably supporting you right now), the regularities of nature, is all arguably a product of an inductive process. But at the local level, you expect the refrigerator to keep working, you don't suscpect the floor boards in the morning. And with people we have particularly keen inductive awareness. If we're looking for clues that we can trust someone, we look for specific things that we believe (rightly or wrongly) predict trustworthiness. Between the errors in our perception and the mistakes in our model of what a trustworthy person is, we probably miss a few and misjudge a few others. But at the heart of our thinking lies a prediction, in this case, that someone is trustworthy. Over time, you can keep track of your record. So here an ordinary judgement, the assessment of someone's trustworthiness, is the product of our ability to recognize and understand some patterns in our experience (especially experience that reveals the characteristics that predict trustworthiness).

We use inductive inference to build up our confidence in which stores to shop at, which advice to take about new music or clothes. We use inductive inference to assess how we are doing at some task. For example, suppose I had convinced myself that I was on track to becoming a great golfer. There's a lot of information about the pattern of accomplishment that leads to becoming a great golfer. It's a pattern. To the extent that I'm honest with myself, I would have to acknowledge that there was little evidence that my game was fitting the pattern. Maybe that's one of the most important things about inductive reasoning: you can often establish conditions that would at least disprove your hyposthesis (in this case, that I was becoming a great golfer).

Now we can see that the scope of inductive evidence encompasses all of our experience and even, to some extent, hypothetical experiences that we feel confident reasoning about, such as thought experiments. Inductive reasoning emerges as we try to fit information and careful observation (evidence) to the patterns of experience we already rely on and to a reliable and testable theory. Whether we're talking about a theory in a scientific discipline, a consequence of "induction in the sciences" or a personal theory you have as a result of ordinary induction, we usually identify a pattern of reasoning from a pattern.

Common Patterns of Argument Found along with Inductive Reasoning

Rather than treat inductive reasoning as fundamentally pattern based (as we did with deductive validity), it makes more sense to say that inductive reasoning involves the "fitting" of data or experience to a (predictive) theory. Then we can say that there are various ways of expressing that "pattern in nature" that the Principle of Induction presumes we will find.

Specific to General

Not surprisingly, ...

General to Specific

Specific to specific (missing premise); found in citation of incidents which are claimed to be typical.

Analogies