This paper relates philosophical and psychological concerns in formulating a theory of teaching and learning. The laboratory exercise is shown to be a paradigm case of the theory, and a means by which students can be taught to think. The laboratory exercise is presented as a means to demonstrate a facet of the conceptual nature of science and to teach students that the construction of an experimental design represents a kind of analogy based upon the idea that what happens in the laboratory is an analogue of what occurs in nature. Anecdotal evidence from classroom experience with this teaching strategy is discussed. (Author/CS)