Online research in philosophy

Teleological terms such as "function" and "design" appear frequently in the biological sciences. Examples of teleological claims include: A (biological) function of stotting by antelopes is to communicate to predators that they have been detected. Eagles' wings are (naturally) designed for soaring. Teleological notions were commonly associated with the pre-Darwinian view that the biological realm provides evidence of conscious design by a supernatural creator. Even after creationist viewpoints were rejected by most biologists there remained various grounds for concern about the role of teleology in biology, including whether such terms are: 1. vitalistic (positing some special "life-force"); 2. requiring backwards causation (because future outcomes explain present traits); 3. incompatible with mechanistic explanation (because of 1 and 2); 4. mentalistic (attributing the action of mind where there is none); 5. empirically untestable (for all the above reasons). Opinions divide over whether Darwin's theory of evolution provides a means of eliminating teleology from biology, or whether it provides a naturalistic account of the role of teleological notions in the science. Many contemporary biologists and philosophers of biology believe that teleological notions are a distinctive and ineliminable feature of biological explanations but that it is possible to provide a naturalistic account of their role that avoids the concerns above. Terminological issues sometimes serve to obscure some widely-accepted distinctions.

This essay examines one of the cornerstones of Leibniz's defense of teleology within the order of nature. The first section explores Leibniz's contributions to the study of geometrical optics, and argues that his "Most Determined Path Principle" or "MDPP" allows him to bring to the fore philosophical issues concerning the legitimacy of teleological explanations by addressing two technical objections raised by Cartesians to non-mechanistic derivations of the laws of optics. The second section argues that, by drawing on laws such as the MDPP, Leibniz is able to introduce a thin notion of teleology that gives him the resources to respond to the most pressing charges of his day against teleological explanations within natural philosophy. Finally, the third section argues that contemporary philosophers have been overly hasty in their dismissal of Leibniz's account of natural teleology, and indeed that their own generally thin conceptions of teleology have left them with few well-motivated resources for resisting his elegant position.

It is often claimed that one of Darwin''s chief accomplishments was to provide biology with a non-teleological explanation of adaptation. A number of Darwin''s closest associates, however, and Darwin himself, did not see it that way. In order to assess whether Darwin''s version of evolutionary theory does or does not employ teleological explanation, two of his botanical studies are examined. The result of this examination is that Darwin sees selection explanations of adaptations as teleological explanations. The confusion in the nineteenth century about Darwin''s attitude to teleology is argued to be a result of Darwin''s teleological explanations not conforming to either of the dominant philosophical justifications of teleology at that time. Darwin''s explanatory practices conform well, however, to recent defenses of the teleological character of selection explanations.

Kant’s position on teleology and biology is neither inconsistent nor obsolete; his arguments have some surprising and enduring philosophical strengths. But Kant’s account will appear weak if we muddy the waters by reading him as aiming to defend teleology by appealing to considerations popular in contemporary philosophy. Kant argues for very different conclusions: we can neither know teleological judgments of living beings to be true, nor legitimately explain living beings in teleological terms; such teleological judgment is justified only as a “problematic” guideline in our search for mechanistic explanations. These conclusions are well supported by Kant’s defense of his demanding analysis, according to which teleological judgment literally applies to a complex whole only where teleology truly explains the presence of its parts.

Among the many tensions in Leibniz’s philosophical system is his tendency to invoke both mechanistic and teleological explanations. Jonathan Bennett, typicalof recent Leibniz commentators, attempts to relieve this difficulty by arguing that teleology for Leibniz is theological posturing and philosophically thin; such a doctrine does not serve to explain the relationship between teleology and mechanism. I argue that Leibniz’s appeal to final causality is both inextricably grounded in his wider metaphysic and helpful in understanding the preconditions for causality in general. To this end I defend the two following claims: 1) It is in part Leibniz’s theory of contingency, and not exclusively theological concerns, that leads him to conclude that the laws of nature must admit of teleological explanations. 2) The finality of the laws of nature, coupled with one of Leibniz’s most promising arguments against occasionalism, are together sufficient to show that teleology must play a role in explanations of the activity of all genuine substances.