Aristotle's Four Causes. New York: Peter Lang 2019. link

Conscientia bei Descartes. Freiburg: Alber Verlag 2006.  link


Journal Articles

"Avicenna’s Agent Intellect as a Completing Cause", History of Philosophy Quarterly 41(1), 2024, 45-72.

"Qualification in Philosophy", Acta Analytica 39(1), 2023, 183-205,  link

"Aitiai as Middle Terms", Journal of Ancient Philosophy 16(2), 2022, 126-148.  link  pdf

"Avicenna on Human Self-Intellection", Arabic Sciences and Philosophy 32, 2022, 179-199.  link

"Quiddities and Repeatables", Synthese 200(3), 2022, 216.  pdf

"Meta Logou in Plato's Theaetetus", Apeiron 54(1), 2021, 109-128.  link

"Self-Knowledge, Estrangement, and Social Metabolism". Monthly Review 70(10), March 2019, 40-57.  link

"The Man Without Properties". Synthese 194(6), 2017, 1989–2006.  link

"Instance is the Converse of Aspect". Australasian Journal of Philosophy 93(1), 2014, 3-20. pdf

"'Insofar as' in Descartes' Definition of Thought". Studia Leibnitiana 43(2), 2011, 145-159. pdf

"Kants Modell kausaler Verhältnisse". Kant Studien 102(3), 2011, 367-384.  pdf

"The Four Causes". The Journal of Philosophy 106(3), 2009, 137-60. pdf

"Cartesian Conscientia". British Journal for the History of Philosophy 15(3), 2007, 455-484. pdf


Book Contributions

"Denken als Probehandeln". In: Wolfram Gobsch & Jonas Held, eds., Orientierung durch Kritik. Festschrift für Pirmin Stekeler-Weithofer. Hamburg: Meiner Verlag 2021, 127-143. 

"Self-Knowledge by Participation". In: Gyula Klima & Alexander Hall, eds., Consciousness and Self-Knowledge in Medieval Philosophy (Proceedings of the Society for Medieval Logic and Metaphysics, vol. 14). Cambridge Scholars Publishing, 2018.

"Über die 'Ursachen' von Texten". In: Verena Klappstein & Thomas A. Heiß, eds., als bis wir sein Warum erfasst haben (Grundlagen der Rechtsphilosophie vol. IV). Franz Steiner Verlag 2017, 161-181. 

"Kategorien" / "Konkrete Einzeldinge". In: Markus Schrenk, ed., Handbuch Metaphysik, Metzler Verlag 2017, 86-89 / 128-134. 

"Aristoteles' Beschreibung der ethischen Tugenden". In: Jan Müller & Jens Kertscher, Lebensform und Praxisform. Paderborn: Mentis Verlag 2015, 173-189. draft pdf

"Descartes". In: Tina-Louise Eissa & Stefan Lorenz Sorgner, eds., Geschichte der Bioethik. Paderborn: Mentis Verlag 2011, 137-148.  pdf

"Is Causation a Relation?" In: Keith Allen & Tom Stoneham, eds., Causation and Modern Philosophy. Routledge 2011, 188-200. pdf



Christian Barth, "Intentionalität und Bewusstsein in der frühen Neuzeit". Philosophische Rundschau 68(1), 2021, p. 60-63.

Thomas Nail, "Marx in Motion". Monthly Review 72(11), April 2021, p. 26-31.

Damien Janos, "Avicenna on the Ontology of Pure Quiddity". Philosophical Quarterly, online 2020.


Dictionary entries

"Disposition". Hans Jörg Sandkühler et al., ed., Enzyklopädie Philosophie. Hamburg: Meiner Verlag 2010.  pdf


Research Projects

Conscientia in Descartes

In Gibt es eine Rehabilitation der Cartesischen Psychologie? I argue that Descartes' distinction between mind and body amounts to a distinction between subjects of moral and epistemic responsibility, and subjects of physical determinations. This way of putting it makes it conceivable that the same entity is subject to both. I show that Descartes indeed describes humans as a mixture of these two kinds of subject, which can, as such, only be understood in an obscure and confused way.

In Conscientia in Descartes, I trace the history of the notion of consciousness (conscientia), which Descartes uses in oder to demarcate the mental. I show that this word, conscientia, has predominantly ethical connotations in the tradition (St. Paul, Augustine, medieval authors), and I argue that Descartes still uses it with these connotations in mind.

Causality, Teleology, and Classification in Aristotle

In Four Causes, I argue that Aristotle's four causes (the material, formal, efficient, and final cause) form a system, so that the final cause of a natural phenomenon stands to its efficient cause as its formal cause stands to its material cause. The formal cause of a natural thing is the actuality of what its material cause is potentially, and the final cause of a natural thing or process is the actuality of what its efficient cause is potentially. This also means that the formal cause is not necessarily the form that a thing actually realizes, but rather the form that it would realize if it were a fully typical specimen of its type.

Plato's Forms

I argue that Plato's forms are not properties but paradigmatic instances of kinds (cf. "Plato's Ingredient Principle"). The form of beauty, for instance, is the generic beautiful thing, and particular things participate in it insofar as they approximate what this form is: a beautiful thing. I further argue that Aristotle still operates with the notion of a generic thing (cf. "The Man Without Properties").


In my work on Descartes, I argue that the distinction between thinking and extended things can be understood to be a distinction of respects, such that the same entity is two different substances, because it can be seen in two different respects (as a subject of ethical and epistemic norms, or as a subject of physical determinations). In my work on Plato and Aristotle, I argue that forms and essences are things in respects: the form of beauty is a beautiful thing exclusively insofar as it is beauty, and other things participate in it insofar as they are what this form is. The locution "insofar as", and with it the notion of an aspect, is therefore central to several of my philosophical interests. I examine it in "'Insofar as' in Descartes' Definition of Thought" and "Instance is the Converse of Aspect".


I am exploring the possibility of practical self-knowledge, that is, a kind of self-knowledge that does not reduce to one's awareness of one's inner states or character traits. If there is practical self-knowledge, it will be constitutive of the self that it knows, in some way to be explained.

Hugh of St. Victor

In a couple of papers on self-knowledge in Hugh of St. Victor, I argue that self-knowledge, according to Hugh, is the knowledge that rational beings have of the proper objects of their distinctive capacities, and that this is knowledge by participation, rather than knowledge by representation.


For Hegel, self-knowledge is the ultimate aim of philosophy: it is distinctively human, and it will be perfect knowledge where it succeeds, in that subject and object are strictly identical. Hegel also argues that human self-knowledge is possible only within a politically organized community, so that when humans know themselves, they know themselves as members of such a community. Marx brings this down to earth by considering the material basis of self-knowledge, which is self-maintenance and reproduction, or, in general: metabolism. This explains Marx's focus on political economy (= social metabolism), labour (= the metabolism between humans and nature), and alienation (= a distortion of social metabolism, which is reflected in a lack of self-knowledge).


Avicenna argues that although the human intellect can never become identical to its object, it can be its own object when it actually understands nothing but itself. Aristotle had argued that the human intellect is in itself merely potential, and therefore needs to be actualized by something external to it before it can be a possible object of knowledge. Avicenna denies this.
In the Pointers and Reminders, Avicenna suggests that the highest form of self-knowledge is achieved when our intellect pays attention to nothing but itself. The question is, basically: Why would this be the highest form of knowledge? First, it does not seem difficult to pay attention to nothing but oneself. Second, it does not seem useful or beneficial to do so. When Avicenna describes pure self-knowledge as the highest form of knowledge, however, he clearly implies that it is both useful and beneficial.


The aim of this project is to give an account of ownership that does not already presuppose that all ownership is or had better be individual, private ownership. Part of the task will be to recover a notion of shared ownership on the basis of the idea that Aristotle appears to entertain when he introduces the notion of ownership (ktesis) in his Politics: The things we own are the things we use as tools in order to lead our life. They are, in Marxian terminology, the essential parts of our extended body. Seen from this angle, one might understand private ownership, the form of ownership that is characteristic of capitalism, as a restriction, i.e. privation of ownership. Roughly, to make ownership private is to grant it only under certain conditions. This happens as part of a general move by which market interactions insert themselves into the human extended metabolism. If what we own is what we need in order to lead our life, capitalism works by withholding from us what we need, and granting it to us only under certain conditions.


Abstracts, Drafts, Manuscripts

Some of the papers in this section are also published in print, some are not.



areas of Interest
master thesis
PhD thesis
hosted by