Phil2004 – Philosophy of Science
Dr. Lawrence Bamikole
November 8, 2012
The search for scientific knowledge extends far back into antiquity. At some point in this quest, at least by the time of Aristotle, philosophers recognized that a fundamental distinction should be drawn between two kinds of scientific knowledge that and why. It is one thing to know that each planet periodically reverse the direction of its motion with respect to the background of fixed stars; it is a different matter to know why. Knowledge of the former type is more descriptive and knowledge of the latter is explanatory. It is explanatory knowledge that provides scientific understanding of our world (Kitcher and Salmon, 1989). Issues concerning scientific explanation have been a focus of philosophical attention from Pre-Socratic (Greek philosophy before Socrates) times through the modern period. “Scientific explanation” is a topic that raises a number of interrelated issues.
According to the Stanford Encyclopedia of Philosophy, an assumption made in numerous discussions is that science sometimes provides explanations rather than “mere description” and that the task of a “theory” or “model” of scientific explanation is to characterize the structure of such explanations. It is further assumed that it is the task of a theory of explanation to capture what is common to both scientific and at least some more ordinary forms of explanation so as to allow for the best possible level of understanding the phenomenon being explained. These assumptions help to explain why discussions of scientific explanation so often move back and forth between examples drawn from bona-fide science (e.g., explanations of the trajectories of the planets that appeal to Newtonian mechanics) and more familiar examples involving the tipping over of inkwells. According to Aristotle, scientific explanations are deductive arguments. But as Aristotle clearly recognized, not all deductive arguments can qualify as explanations. Even if one accepts the idea that explanations are deductive arguments, it is not easy to draw a clear distinction between those arguments that do qualify and those that do not.
In 1948 Carl G. Hempel and Paul Openheim published an essay, “Studies in the Logic of Explanation,” which was truly epoch-making. It set out, with unprecedented precision and clarity, a characterization of one kind of deductive argument that according to their account does constitute a legitimate type of scientific explanation. This became known as the Deductive-Nomological model and is also referred to by some as the Covering Law model. This article provided the foundation for the old consensus on the nature of scientific explanation that reached its height in the 1960s. This model is based on the premise that working scientific explanations can be derived from laws that are created from the regular observation of phenomena, which can then be used to successfully predict the subsequent re-application of these laws. Thus, “…a phenomenon can be explained by deducing it from a set of premises that includes at least one law that is necessary to that deduction” (Hempel, 1965). This paper seeks to not only expound on the structure of this model and its various constituents, but to also critically examine its strengths and weaknesses in its use as a model of explanation in science.
According to the Deductive-Nomological Model, a scientific explanation consists of two major “constituents”: an explanandum, a sentence “describing the phenomenon to be explained” and an explanans, “the class of those sentences which are adduced to account for the phenomenon” (Hempel and Oppenheim, 1948). For particular events, the DN model ascribes to the following schema (Papineau, 1995):
In this diagram C1 – Ck are statements...