Editorial Aristotelian Metaphysics: Essence and Ground Riin Sirkela , Tuomas Tahkob aDepartment of Philosophy, University of Vermont bDepartment of Philosophy, University of Helsinki is special issue of Studia Philosophica Estonica centers aroundAristotelian metaphysics, construed broadly to cover both scholarly research on Aristotle's metaphysics as well as work by contemporary metaphysicians on Aristotelian themes. Aristotelian metaphysics is a growing tradition. ere are increasingly more metaphysicians identifying themselves as 'Aristotelians', and there are more scholars looking at work in contemporary metaphysics to advance scholarship. Indeed, there have already been a number of volumes showcasing this 'Aristotelian turn', including Daniel D. Novotný's and LukášNovák'sAristotelian Perspectives inMetaphysics (2014), Edward Feser's Aristotle onMethod andMetaphysics (2013), and Tuomas Tahko's Contemporary Aristotelian Metaphysics (2012). e contribution this special issue makes to the ongoing discussion is twofold. First, the special issue promotes a deeper interaction between scholars of Aristotle and contemporary metaphysicians. We hope that the papers encourage people working in the history of philosophy to relate to contemporary discussions and people working in contemporary metaphysics to engage with Aristotle and Ancient scholarship. Second, the special issue is unied in its focus on two themes in Aristotelian metaphysics, essence and grounding. e papers address questions concerning fundamentality and dependence, ontological independence or priority, the causal priority of forms, the unity of grounding, the reduction of grounding to essence, the unity of essence, the roles of essence, and explanation and denition. We hope that this issue opens up fresh and exciting avenues for future research both in Ancient scholarship as well as in contemporarymetaphysics. A brief summary of the volume's papers follows. Justin Zylstra takes his cue fromAristotle's claim in Categories 5 that any Corresponding author's address: Riin Sirkel, 70 SouthWilliams Street, Burlington, VT, 05401, USA. Email: riin.sirkel@gmail.com. © All Copyright Authors Studia Philosophica Estonica (2014) 7.2, 1–4 Published online: December 2014 Online ISSN: 1736–5899 www.spe.ut.ee http://dx.doi.org/10.12697/spe.2014.7.2.01 2 Editorial items alike in nature do not dier in respect to fundamentality, and he uses it to explore connections between relative fundamentality and dependence. In neo-Aristotelian discussions these two notions are oen taken to be synonymous, but Zylstra shows that dependence is neither necessary nor sucient for relative fundamentality. He develops an account of relative fundamentality in terms of likeness in nature, and applies his account to some controversial questions that arise in Aristotle's Categories. Margaret Cameron draws on Aristotle's notion of homonymy to propose a solution to the problem of the unity of grounding. While proponents of grounding take it to be a unied phenomenon, some recent criticisms take issue with this assumption, arguing that there is heterogeneity to the notion of grounding that makes it useless for performing the negrained work its proponents want it to do. Cameron shows there is a third option between characterizing grounding as either a unied phenomenon or merely as equivocal (i.e. same in name only): grounding is an Aristotelian homonym, and, more specically, a core-dependent, systematic homonym. Her account accommodates the ideas driving both unity and heterogeneity and is compatible with the Aristotelian-orientation of philosophers who make use of the notion of grounding. Pablo Carnino tackles a topic which is receiving increasing attention in the literature on grounding, namely, the analysis of grounding in terms of essence. Carnino evaluates Fabrice Correia's attempt to reduce grounding to essence and argues that Correia has underestimated one objection to this analysis, originally suggested by Kit Fine. Carnino improves on Fine's objection and shows that it can still be considered an obstacle to the analysis of ground in terms of essence. Moreover, Carnino develops two novel objections to the analysis although he considers only one of them to be truly challenging. e upshot of Carnino's paper is that the operationalist denition of grounding, as defended, for instance, by Kit Fine, stands its ground. Ryan Christiansen continues on the topic of essence, arguing that there are (at least) three dierent notions of essence, each of which is irreducible to the others. ese notions of essence are essence as constancy amid change, essence as explanation, and essence as necessity. First, Christensen comments on the debate between the neo-Aristotelian proponents of 'real essence' and the Kripke-Putnam inuenced view of essential properties of a thing as the properties that the thing cannot exist without. ese correspond to essence as explanation and essence as necessity. He argues that the debate between these two schools is not substantial because they use the notion of essence in dierent ways. Christensen then goes on to discuss each of the notions of essence in more detail and identies several dierent questions related to these notions. He concludes that each of these notions of essence Riin Sirkel 3 has its important job, but no one notion can do all the work associated with essence. Lucas Angioni examines questions concerning essence, necessity and explanation in Aristotle's Posterior Analytics. In particular, he wants to know what Aristotle means when he says that demonstrations must proceed from necessary principles. Angioni challenges the interpretation that collapses a necessary character of a principle into its necessary truth as a sentence and argues that being a necessarily true sentence is not sucient for being a necessary principle. In his interpretation, a necessary principle is necessary for attaining the fully appropriate explanation of a given explanandum, and the most appropriate explanatory factor is what makes the explanandum what it is. is account of necessary principles helps in understanding Aristotle's thesis that demonstrations depend on essences and supports the idea that necessary properties are grounded in essential properties. Kathrin Koslicki's focus is on the central books of Metaphysics and on Aristotle's thesis of the form's priority over matter and matter-form compound. She starts with Aristotle's claim inMetaphysics Z.17 that form is the primary cause and principle of a matter-form compound's being what it is, and she examines Aristotle's motivation for locating the primary causal responsibility for a compound's being what it is with the form rather than the matter. Koslicki uses Aristotle's account of the threefold priority of the actual over the potential inMetaphysicsΘ.8 to clarify the priority of form over matter. She develops an explicitly causal account of the form's priority, arguing that the priority of form over matter in denition, time, and substance is best explained by appeal to the role of form as the formal, ecient, and nal cause of the matter-form compound respectively. Michail Peramatzis' focus is also on the central books ofMetaphysics, but he is concernedwith questions regarding sameness and denition. His starting point is the apparent inconsistency between Aristotle's claims in Metaphysics Z and H. Aristotle claims that the essence or form is the same as its essence (e.g. being a human = being a rational soul) and that the essence is dened in terms of its essence (being a human =de f being a rational soul). On the other hand, Aristotle claims that the substance-kind is not the same as its essence (human ≠ being a human), and yet the substance-kind is de- ned in terms of its essence (human =de f being a human), which would imply that the substance-kind is the same as its essence. Peramatzis considers dierent strategies to overcome this inconsistency, which all prove to be problematic. He locates the problemwithin their shared assumption that the relevant notion of sameness is that of strict numerical identity, and develops an account of essential sameness and denition. Christie omas broadens the discussion by considering Plato's views 4 Editorial on metaphysical explanation. She begins with Aristotle's criticism of Plato's participation relation, focusing on the charge that participation could not serve as a genuinely explanatory relation. In response, omas develops an account of participation and metaphysical explanation by identifying different states of the development of Plato's ontology. She argues that in his later dialogues Plato distinguishes between two types of metaphysical predication, and she follows Pelletier and Zalta in characterizing the distinction as that between encoding and exemplication. She shows that such an account of predication renders unfounded Aristotle's charge that participation is mere metaphor and empty talk. Travis Dumsday's paper concludes the volume. Dumsday focuses on a somewhat neglected problem concerning essence, sometimes known as the problem of unity. is problem relates to natural kind essences in particular. eproblemof unity concerns the relatedness of certain essential properties, such as themass and charge of a particular electron. ese properties are inherently separable, but they are also intimately connected in the essence of the electron. Dumsday asks: What explains this connection? Dumsday examines various approaches to this problem but proposes that the late E.J. Lowe has perhaps made the most progress with regard to it based on Lowe's four-category ontology. Dumsday examines Lowe's solution and identies a possible problem in it, but he suggests a rejoinder as well. Ultimately, Dumsday proposes that it may be possible to revise Lowe's theory in such a way that a promising line of research regarding the problem of unity can be developed. Bibliography Feser, E. (ed.) (2013). Aristotle on Method and Metaphysics, Palgrave. Novotný, D. and Novák, L. (eds) (2014). Aristotelian Perspectives in Metaphysics, Routledge Studies in Metaphysics, Routledge. Tahko, T. (ed.) (2012). Contemporary Aristotelian Metaphysics, Cambridge University Press.