Leibniz, Husserl and Neurophysiology

This project is about the relations between perception, consciousness, and time. It refers to Leibniz not for philological reasons but to work towards a philosophical orientation (in Wittgenstein's terms a "übersichtliche Darstellung") in a conceptual maze in which Leibniz already tried to find his way and found some very useful paths. Therefore his work shaped much of the later discussions, and seems still to be defensible as a very useful compass in many respects. This methodical approach is similar to the one Sellars, Mackie and Strawson had each chosen when they referred to Kant and Locke.

The first aim is to argue against a concept of perception that (i) is restricted to conscious states and/or (ii) views consciousness as a result of "outer" or "sense" perception. This will be done on the basis of Leibniz’s notion of unnoticeable perceptions and by looking at recent neurological research. Leibniz in his idea of a parallelism (a "pre-​established harmony") between mental and bodily states thought very thoroughly about what a physical correlate of a mental (perceptual) state could mean; and his anti-​reductionistic reflection will be taken up again against the background of recent empirical findings in psychophysics and neurophysiology. This leads to an interpretational framework in which certain brain responses are understood as physical correlates of unnoticeable perceptions. So, for instance, the interpretation of the experiments by Libet et al. turns out to be about (the mental accessibility of) perception and not—or at least not directly—about free will.

The next step is to argue that consciousness can be understood as being a result of (unnoticeable) perceptions. Here Leibniz's concepts of representational content and appetitive structure of perception can be understood as constituting an elementary form of intentionality. So, apart from obvious relations to contemporary analytic philosophy of mind, recourses to phenomenology are also possible, and indeed helpful to further explicate a Leibnizian position. In particular, considered in the light of Husserl’s analysis of time consciousness, it is argued that temporal awareness (as an appetitive structure) is constitutive of perception and therefore also of consciousness. What follows is a so called tensed view of time with respect to perception.

In the final part of the project this has to be related back to brain responses, i.e. the physical correlates of Leibnizian perceptions. It will be argued that their temporal order is tenseless; i.e., that physical events—other than contents and appetitions of perceptions—are not fundamentally past, present or future. There are then two types of temporal order (namely tensed and tenseless) which underlie the difference between the realms of perception and of physics. So instead of referring to God as a "pre-​establisher" of the parallelism between perceptual (including mental) states and bodily states, this parallelism can be interpreted as a consequence of a homeomorphism between tensed and tenseless temporal relations.


  • N. Sieroka (2018): Theoretical Construction in Physics: The Role of Leibniz for Weyl's "Philosophie der Mathematik und Naturwissenschaft". Studies in History and Philosophy of Modern Physics 61 (1), pp. 6-17.

  • N. Sieroka (2016): Retrospective Analogies: Means for Understanding Leibniz's Metaphysics. In: "Für unser Glück oder das Glück der Anderen" (Vorträge des X. Internationalen Leibniz-​Kongresses), ed. by W. Li. Olms, Hildesheim, Band IV, pp. 285-​299.

  • N. Sieroka (2015): Leibniz, Husserl, and the Brain. Palgrave Macmillan, Basingstoke.

  • M. Andermann, R. Patterson, M. Geldhauser, N. Sieroka, A. Rupp (2014): Duifhuis Pitch: Neuromagnetic Representation and Auditory Modeling. Journal of Neurophysiology 120 (10), pp. 2616-​2627.

  • N. Sieroka (2011): Neurophenomenology of Hearing: Relations to Intentionality and Time Consciousness. XXII. Deutscher Kongress für Philosophie, open access

  • N. Sieroka (2011): Leibniz' Theorie der Wahrnehmung und ihre aktuelle Relevanz für die Philosophie des Geistes. In: Natur und Subjekt (IX. Internationaler Leibniz-​Kongress), ed. by H. Breger, J. Herbst und S. Erdner. Hannover, pp. 1090-​1099.

  • N. Sieroka (2009): Ist ein Zeithof schon genug? – Neurophänomenologische Überlegungen zum Zeitbewusstsein und zur Rolle des Auditiven. Philosophia Naturalis 46 (2), pp. 213-​249.

  • A. Rupp, N. Sieroka, A. Gutschalk, T. Dau (2008): Representation of Auditory Filter Phase Characteristics in the Cortex of Human Listeners. Journal of Neurophysiology 99 (3), pp. 1152-​1162.

  • N. Sieroka, H.G. Dosch (2008): Leibniz's "Perceptions Insensibles" and Modern Neurophysiology. Studia Leibnitiana 40 (1), pp. 14-​28.

  • N. Sieroka, H.G. Dosch, A. Rupp (2006): Semirealistic Models of the Cochlea. Journal of the Acoustical Society of America (JASA) 120 (1), pp. 297-​304.

  • N. Sieroka (2005): Quasi-​Hearing in Husserl, Levinson, and Gordon. Journal of the British Society for Phenomenology 36 (1), pp. 4-​22.

  • N. Sieroka (2004): Neurophysiological Aspects of Time Perception. Dissertation, Universität Heidelberg.


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