Inferring and Explaining

Pink Martini’s songs again and see what hap- pens. What is being proposed here is a classic little experiment—the kind of thing that some philosophers and scientists say is the defning condition of real science. I hope to convince you in the next couple of chapters that there is some- thing brilliantly right about this claimbut, at the same time, dangerously misleading. A Pretty Picture of Science Here is an idealization about the natural sci- ences.Te scientist is really smart and is trained to go about her business in a very special, almost ritualized, way. She goes out and observes the world. Being smart and being trained to be a careful observer, she notices things. Sometimes she is puzzled by the things she observes and she asks questions, Why am I observing this? She starts looking for an explanation . Being smart and creative she thinks about this really hard and comes up with a possible answer—a hypothesis or a theory . Tis is all fne and good, but according to the pretty picture, it’s only now that the rules of science kick in. It’s not good enough to just have a theory; the theory must now be tested. Te scientist must devise an experiment and let the results of the experi- ment determine the fate of her theory. Bear with me for a bit of technical stuf in symbolic logic. Logicians talk about conditionals , “if . . . then” sentences. Tere are two valid infer- ences that followdirectly froma true conditional. 1. If the fgure is a plane right triangle, then the interior angles total 180°. 2. The fgure is a plane right triangle. 51 3. The interior angles total 180°. Tis inference is called modes ponens . A kind of mirror image inference is called modes tollens . 1. If the fgure is a plane right triangle, then the interior angles total 180°. 2. The interior angles do not total 180°. 3. The fgure is not a plane right triangle. Finally, there is a tempting inference that is not valid but is rather a logical fallacy, afrming the consequent . new data and exPerImentatIon 1. If the fgure is a plane right triangle, then the interior angles total 180º. 2. The interior angles total 180º. 3. The fgure is a plane right triangle. You can easily spot the fallacy by noting that the fgure might total 180° because it’s a triangle, but, at the same time, not be a right triangle but rather, say, an equilateral triangle. OK, so what does all this have to do with the pretty picture of science and maybe Johnson’s iPod? Well, suppose the conditional sets up something we might expect to see in an experi- mental circumstance, given the theory we are testing is true. 1. If the theory is true, we will see . . . in the experiment. By the inference of modes tollens , we will be able to falsify the theory by disconfrming it in an experiment.