L Liceti, Fortunio Born: 1577, Rapallo Died: 1657, Padua Andreas Blank Alpen-Adria Universität Klagenfurt, Department of Philosophy, Klagenfurt, Austria Abstract Liceti is the last of the great Paduan Aristote- lians. His extensive works cover all areas of natural philosophy, and while Liceti is always careful to give full expositions of the diverging strands of Aristotle interpretation on any given subject, he does not hesitate to use traditional conceptual frameworks to develop innovative theories. One example for this is his conception of rational souls as immaterial but quantitative, extended beings. To explicate this conception, he uses an analogy between rational souls and the theory of light developed by the eclectic medieval natural philosopher Albert the Great, who argued that the dependence of light on a source from which it arises through emanative causation renders light existentially indepen- dent from the medium that it illuminates. Another innovative aspect of Liceti’ s thought can be found in his version of the traditional theory of spontaneous generation. Unlike any thinker before him, he held that the substantial forms of living beings arising through spontaneous generation could be understood as material structures that arise through the completing of previously existing, but essen- tially different material structures. Biography Fortunio Liceti is an eclectic Aristotelian natural philosopher who held professorships in philoso- phy at the Universities of Pisa (from 1605), Padua (from 1609), and Bologna (from 1637) and took up a chair in theoretical medicine at the University of Padua in 1645. His intellectual autobiography (Liceti 1634) lists 24 published books, some of them very extensive, as well as 25 unpublished book manuscripts, some of which were published afterwards (see Lohr 1978, 540–541; Ongaro 2005). His writings cover all fields of natural philosophy, with a particular emphasis on biolog- ical and medical issues (for overviews, see Ongaro 1964, 1965). In particular, he is the author of a widely cited work on monsters (Liceti 1616b; see Céard 1977, 442–447, 451–456; Hanafi 2000, 34–47). From a philosophical point of view, two of his most original contributions relate to the theory of spontaneous generation (see Castellani 1968; Hirai 2007, sect. 3, 2011) and the metaphys- ics of immaterial extension (see Blank 2013). With respect to the former issue, he proposes an analysis of the notion of substantial form of spon- taneously generated living beings in terms of material structures that are in a rudimentary way # Springer International Publishing AG 2018 M. Sgarbi (ed.), Encyclopedia of Renaissance Philosophy , https://doi.org/10.1007/978-3-319-02848-4_1128-1