ABSTRACT
One of the most common tasks of science is to provide explanations. The problem of induction addresses the question of prediction-saying what will happen inferred from what has been observed. But science is interested not only in questions of what will happen but also in questions of why what has happened did happen. If faced with an epidemic with new symptoms we may want science to tell us how the epidemic will progress, how many people will develop the symptoms, for how long, and in what concentrations. We will also hope that science will come up with an answer as to why this epidemic has broken out and why it is that people show the symptoms they do. Though distinct, the two questions are linked. One way of predicting how the epidemic will progress would be to discover and learn about the organism that causes it. That is, armed with the explanation of what we have already observed we may be able to predict what we will observe. Conversely, if there are alternative possible explanations available, then we may be able to discover the real explanation by checking what actually happens against the different predictions made on the basis of each of the competing explanations.
