INTRODUCTION

This chapter and the next defend five related claims. In the process, a philosophical account of theoretical modeling, as an explanatory practice, is outlined. The philosophical model is then applied to the controversies that prompted this philosophical excursion in the first place, the controversies identified in Chapter Five.

Here are the five claims. First, there is a tension in our explanatory practices between pursuit of the detailed knowledge of causal mechanisms and processes needed for successful causal explanation on the one hand, and pursuit of systematizing or unifying frameworks that will enable us to cover a broad range of cases with a minimum expenditure of cognitive capital on the other. This leads to the second thesis: Salmon's two venerable intuitions regarding scientific explanation correspond to distinct explanatory virtues, and while there may be some worlds where explanations virtuous on one score are likely to be virtuous on the second as well, ours does not appear to be such a world – at least not when it comes to ecology. The third thesis is that actual scientific explanations embody elements of both virtues, sometimes trading off systematizing power for a clearer grasp of causal structure and sometimes making the trade-off in the other direction, depending on the explanatory needs at hand. Thus actual explanations can be located on a kind of continuum, with “pure” causal explanation and “pure” systematization as the idealized endpoints, and with location on the continuum signaling the mixture of the two virtues to be associated with a given explanation.