Teleology and the Life Sciences: Between Limit Concept and Ontological Necessity BARBARA MURACA 1. Introduction Against the background of the current discussion about self-organization theories and complexity theories and their application within biology and ecology, the question of teleology gains a new significance. Some scholars insist on the total elimination of any reference to teleology from the realm of the natural sciences. However, it seems especially hard to eradicate tele- ological expressions from scientific language when the issue of under- standing living beings is at stake. For this reason, other scholars opt for a middle path that allows for some teleological language. Yet, it is an open question whether teleological expressions are to be considered as playing a merely metaphorical or a necessary heuristic role in the sciences. Moreo- ver, the ontological presuppositions, which underpin different positions in the debate, need to be depicted and analyzed. This paper aims at addressing the question of teleology within the life sciences by taking into account both Kant's critical philosophy and White- head's ontology. My analysis starts with Georg Toepfer's distinction among different concepts of teleology and then focuses on the role of "in- ternal purposiveness" (innere ZweckmaBigkeit) for biology today. I show how purposiveness (ZweckmaBigkeit; hereafter: ZM) corresponds to a very complex form of reciprocal causation (Wechselwirkung) rather than to any model of final causation. Drawing on Kant's analysis of "natural purposes" in the Critique of Judgment (CJ) as well as self-organization theory, I claim that reciprocal causation - however complex it might well be - is not sufficient to describe living beings adequately. However, since the natural sciences are still caught up in the presuppositions of modern scientistic and materialistic ontology, a step beyond mere efficient causation seems to be impossible within their methodological framework. And yet, as I will DRAFT In: Koutroufinis, S.(2014): Life and Process. Towards a New Biophilosophy. Berlin/Boston: De Gruyter