nl en



Admission requirements

Some background in theoretical philosophy.


The notion of a category has occupied a central place in the philosophical tradition, although different philosophers have understood the notion in different ways. A good tentative definition says that a category is a concept of the highest degree of generality. This definition leaves room for specifying what is then meant by a concept and what by the generality of a concept.

The first part of this seminar will be devoted to the study, firstly, of Aristotle’s Categories and its very influential interpretation by Porphyry, and secondly, of relevant sections in Kant’s Critique of Pure Reason (especially the Analytic of Concepts). These are the key writings on, and form the starting point for any investigation into, the notion of category. We will see that they offer quite different conceptions, and indeed by specifying in different ways the notions of concept and generality as they occur in our tentative definition above.

In the second part of the seminar we will turn to three central philosophers of the late 19th and early 20th century: Frege, Husserl, and the early Wittgenstein. Here the distinction between language and things spoken about receives more attention, leading to a distinction between semantical and ontological categories. One question which then naturally arises is whether semantical categories, and thereby language, somehow mirror ontological categories. With Wittgenstein, finally, we have to ask whether by attempting to say something about categories (or `formal concepts’ as he called them) we perhaps overstep the border of what can meaningfully be spoken about.

Course objectives

Course objectives will be posted on Blackboard by the start of the course.


See Collegeroosters Wijsbegeerte 2012-2013, MA Philosophy
See Timetables Philosophy 2012-2013 , MA Philosophy

Mode of instruction

  • Seminars

Assessment method

  • Term paper (60 %)

  • Three written one-page summaries of texts we read (25 %)

  • Class participation (15 %)

The length of the term paper should be roughly 15 pages for MA students.


Outside the seminar room e-mail will be the preferred mode of communication between instructor and students. Blackboard may be used as a forum for discussion among the students.

Reading list

At the beginning of the semester students should have access to:

  • Aristotle, Categories (The revised Oxford translation by J.L. Ackrill). This is 20 pages of text, and may be copied from The Complete Works of Aristotle, edited by J. Barnes, available in the Studiezaal Wijsbegeerte of the University Library.

  • Porphyry, Introduction (Translated by J. Barnes). The text of roughly 20 pages will be made available for copying, but students might want to acquire the book to read the commentary by Barnes.

  • Kant, Kritik der reinen Vernunft/Critique of Pure Reason/ Kritiek van de zuivere rede. (students should have access to both the A and the B edition)

Material relating to Frege, Husserl, and Wittgenstein will be announced during the semester.


Please register for this course on uSis.
See Inschrijven voor cursussen en tentamens

Study Abroad students, please see the Study in Leiden website for information on how to apply. See also Registration for courses and examinations

Registration Studeren à la carte and Contractonderwijs

Aanmelden voor Contractonderwijs via:
Na aanmelding ook inschrijven voor cursus en tentamen via uSis

Contact information

A.M. Klev, MSc, MPhil