Any type of efficient causality is typically associated with being an unscientific explanation—explanations nonetheless but unscientific. It is believed that if biology, chemistry, physics, etc. rested explanations in final causation then it would be a science stopper. This is where the distinction between Duhemian science and Augustinian science must be made. I would deny the use of Duhemian science. This method, or philosophy, has a goal of stripping science from all metaphysical imports. Augustinian science is open to metaphysical presuppositions with science. Francis Bacon and Descartes used and allowed for formal and final causation in scientific explanation. Newton entered science and postulated that the universe was entirely mechanistic, which was a denial of Baconian and Cartesian science (at least their versions of scientific explanation) but offered no explanation for the appearance of final causation and efficient causation. Darwin came along and provided a plausible material mechanism for the appearance of final and efficient causation (at least for the special science of biology). In the mid 1800’s William Whewell was the first to restrict science to only mean natural science. Pierre Duhem followed this idea and constructed a methodology, which barred explanations to material causes. For instance, agent causation is completely compatible with Augustinian science but is prohibited as a scientific explanation in Duhemian science. Agent causation is something that can be observed but isn’t necessarily reductionistic in the material sense as with material causation because agent causation has metaphysical import.
Nomic necessity plays an important role in factoring in the efficacy of efficient causation in natural explanations. Sometimes the demand for efficient causation as an explanation will show that what happened had to happen in a very strong sense, that its occurrence was necessary and not just physically necessary, in light of what the laws of nature just happen to be, but necessary as a matter of rational intelligibility or logic. Thus, the laws of nature may not be contingently true but necessarily true. Ceteris paribus laws treat non-strict regularities as nevertheless laws. It is a commonly accepted view that proprietary laws of the special sciences take this form. If we deny that there are such ceteris paribus laws in the special sciences, we must either deny that their explanations are scientific or find another source for their explanatory powers. Rosenberg argues that the former is a nonstarter and implausible. Concerning the latter perhaps desires and beliefs bring about or cause actions (efficient causation), but that is not how they explain them. As Jerry Coyne put it, “If we’re to defend evolutionary biology, we must defend it as a science: a nonteleological theory in which the panoply of life results from the action of natural selection and genetic drift action on random mutations.” Modern science is built on this teleological rejection. By treating the physical world exclusively as a realm of law (necessitarian or ceteris paribus), modern science extrudes purpose from physical nature. The fulfillment of purpose is the fulfillment of function. To conceive nature as a realm of law is to conceive it as a self-sustaining causally closed system with no need for efficient and teleological causation.
There is not supposed to be anything teleological left in translating the behavior of laws (necessity or otherwise) and scientific explanation. Such translations must be purely non-efficient cause and effect, which are supposed to account for teleological explanations and regularities. Knowledge and intentionality are entirely natural phenomena, explicable in terms of causal relations. Teleological properties are taken to consist of a set of causal and historical relations. All the purpose has been cashed in for causation. This purely causal account of purpose in terms of a consequence etiology is called “selected effects” analysis. As previously mentioned, correlating causal relations with teleology connects knowledge with reliability. Such certainty would require a necessitarian or ceteris paribus understanding of natural laws.
Discovering the function of something is purely the discovery of its causal role in the macrocosm. Thus, causal role is equivalent to function and function is equivalent to teleology while teleology is underdetermined in definition because of the absence of efficient and final causation. Scientific explanation has traditionally been met with dissatisfaction by those who demand that such explanation show the purpose of natural processes and not just show how they came to be. According to Rosenberg, teleological explanations are legitimate in the social sciences while the natural sciences are bereft efficient and final causation. The why question is reduced to the how question and is equivocal in explanation.
 Alexander Rosenberg, Philosophy of Science (New York: Routeledge, 2012), 98.
 Ibid., 101-02.
 Jerry Coyne,, “Truckling to the Faithful: A Spoonful of Jesus makes Darwin Go Down,” posted on his blog Why Evolution is True on April 22, 2009, http://whyevolutionistrue.wordpress.com/2009/04/22/truckling-to-the-faithful-a-spoonful-of-jesus-helps-darwin-go-down/ (accessed March 7, 2012).
 Michael Williams, “Must Naturalists be Realists?” in The Nature of Nature. Eds. Bruce Gordon and William Dembksi (Wilmington, DE: ISI Books, 2011), 251.
 Robert Koons, “The Incompatibility of Naturalism and Scientific Realism,” in The Nature of Nature. Eds. Bruce Gordon and William Dembksi (Wilmington, DE: ISI Books, 2011), 218.
 Rosenberg., 104-05.
 Koons, 219.
 Ibid., 112-13.