"The effort is to bring up into view every rational explanation of new phenomena, and to develop every tenable hypothesis respecting their cause and history. The investigator thus becomes the parent of a family of hypotheses: and, by his parental relation to all, he is forbidden to fasten his affections unduly upon any one."This idea is particularly important in the field sciences where the scientist is often making observations about what you might call a "natural experiment," which may have occurred at some point in the past. If you have but a single hypothesis it might be easy to find evidence than in your view validates the hypothesis (causes the effect). The example that Chamberlin uses is the origin of the Great Lakes. You could have a hypothesis that the lakes were gouged by glaciers and you could find plenty of evidence that supports your hypothesis. But you would still be (partially) incorrect. A better thing to do is to list many potential explanations of your phenomena and then test them all. What you may find is that there is a different "right answer" (or that there are multiple causes). The Great Lakes were occupied by glaciers, true, but they were river valleys before the glaciers, and some of them were river valleys because they were low areas as a result continental rifting that occurred more than a billion years ago. Only by proposing and testing multiple hypotheses could you find the best possible explanation.
So how does this apply to the common cold? I came down with a severe sore throat suddenly on Wednesday afternoon. I formed several working hypotheses as to the cause and the progression of the sore throat:
- strep throat
- a cold
- the intestinal flu that was rampant in husband's hometown
- just a plain jane vanilla sore throat
- If strep then I would develop a high fever. If I develop a fever, I would get a strep culture.
- If a cold, my sore throat would dissipate when the post-nasal drip ceased and the nose blowing took over.
- If the flu, well, that one would be pretty obvious, don't you think? Intestinal symptoms should start within 24 hours of the beginning of the sore throat.
- If tonsillitis, I'm not sure. I've never had it.
- Plain-jane: sore throat would disappear without development of other symptoms.