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Thomas Kjeller Johansen

Professor

Email t.k.johansen@ifikk.uio.no

Mobile phone +47 40 59 57 38

Room GM 444

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Visiting address Blindernveien 31 Georg Morgenstiernes hus 0313 OSLO

Postal address Postboks 1020 0315 Blindern

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My research interests lie within the Presocratics, Plato and Aristotle, particularly, their theories of mind, epistemology and natural philosophy

Before coming to Oslo in 2016 I was Professor of Ancient Philosophy at the University of Oxford, and taught at the Universities of Edinburgh and Bristol. I am currently leading the research project, The Mathematization of Nature (ERC Advanced Grant), which investigates Plato´s mathematical world view, how it was influenced by the Early Pythagoreans and interpreted by Plato’s students in the Academy, and was previously PI of Modelling Human Happiness (RCN grant), an interdisciplinary research project which develops models of happiness inspired by ancient philosophy.

Tags: Philosophy

Main works

Aristotle, Metaphysics Α-α, Clarendon Aristotle Series, OUP 2025
The Powers of Aristotle’s Soul, OUP 2012
Plato’s Natural Philosophy. A Study of the Timaeus-Critias, CUP 2004
Aristotle on the Sense-Organs, CUP 1997

Johansen, Thomas Kjeller (2022). ‘A cosmos before the cosmos? Aristotle´s criticism of the pre-cosmic traces in the Timaeus’. Chôra. ISSN 1583-8617. 20, p. 55–70. Full text in Research Archive
Johansen, Thomas Kjeller (2021). 'Plato on Perceiving through the Whole Body'. Oxford Studies in Ancient Philosophy (OSAP). ISSN 0265-7651. 60, p. 95–143. Full text in Research Archive
Johansen, Thomas Kjeller (2021). 'Introduction'. In Johansen, Thomas Kjeller (Eds.), Productive Knowledge in Ancient Philosophy: The Concept of Technê. Cambridge University Press. ISSN 9781108641579. p. 1–14. Full text in Research Archive
Johansen, Thomas Kjeller (2021). ´Crafting the Cosmos: Plato on the limitations of divine craftsmanship´. In Johansen, Thomas Kjeller (Eds.), Productive Knowledge in Ancient Philosophy: The Concept of Technê. Cambridge University Press. ISSN 9781108641579. p. 86–108. Full text in Research Archive
Johansen, Thomas Kjeller (2021). 'Monism in Aristotle’s Metaphysics I.3–5'. Peitho. Examina Antiqua. ISSN 2300-9004. 12(1), p. 19–40. doi: 10.14746/PEA.2021.1.2. Full text in Research Archive Show summary
Scholars have often seen Parmenides as entirely opposed to earlier materialistic philosophy. In this paper I argue that what is more striking in Aristotle’s Metaphysics Book I is the degree of continuity that he sees between Parmenides and the material monists. I explore this coupling of Parmenides with the material monists to understand better what he takes to be distinctive and problematic with Parmenides’ monism.
Johansen, Thomas Kjeller (2020). ‘From Craft to Nature: The Emergence of Natural Teleology’. In Taub, Liba (Eds.), The Cambridge Companion to Ancient Greek and Roman Science. Cambridge University Press. ISSN 9781316136096. p. 102–120. Full text in Research Archive
Johansen, Thomas Kjeller (2020). ‘Soul, Life, and Nutrition in the Timaeus’. In Bartos, Hynek & King, Colin (Ed.), Heat, Pneuma, and Soul in Ancient Philosophy and Science. Cambridge University Press. ISSN 9781108476737. p. 121–139. Full text in Research Archive
Johansen, Thomas Kjeller (2020). 'Plato's Teleology'. In McDonough, Jeffrey K. (Eds.), Teleology. A History. Oxford Philosophical Concepts. Oxford University Press. ISSN 9780190845704. p. 14–38. Full text in Research Archive
Johansen, Thomas Kjeller (2020). 'Technê in Aristotle’s taxonomy of knowledge'. In Fridland, Ellen (Eds.), The Routledge Handbook of Philosophy of Skill and Expertise. Routledge. ISSN 9781138744776. p. 76–87. Full text in Research Archive
Johansen, Thomas Kjeller (2019). ´The principle that “like perceives like” in Theophrastus´ De Sensibus´. Rhizomata. ISSN 2196-5102. 7(2), p. 1–22. doi: 10.1515/rhiz-2019-0007. Full text in Research Archive
Johansen, Thomas Kjeller (2018). Teknokrati og demokrati: Platon og Aristoteles om politisk ekspertise. Agora Journal for metafysisk spekulasjon. ISSN 0800-7136. 2-3, p. 177–198. Full text in Research Archive
Johansen, Thomas Kjeller (2017). ‘The Separation of Soul from Body in Plato’s Phaedo'. Philosophical Inquiry. ISSN 1105-235X. 41, p. 17–28. doi: 10.5840/philinquiry2017412/312. Full text in Research Archive Show summary
The view that the soul can exist separately from the body is commonly associated with dualism. Since Plato’s Phaedo (Phd.) argues that the soul is immortal and survives the death of the body, there seems to be reason to call Plato, in that dialogue at least, a ‘dualist’. Yet, as we know, there are many kinds of dualism, so we have thereby not said very much. Let me therefore start with some distinctions. First of all, we can distinguish between two kinds of dualism which say that the soul is a different kind of substance from the body. On one version, call it ‘strong’ substance dualism, no properties of mind can also be properties of body. Mind is defined as a kind of thing that uniquely has a certain property or set of properties, say consciousness, just as body is defined by its unique properties, say spatial extension. This would seem to be Descartes’ view. On another version, call it ‘weak’ substance dualism, no essential or defining properties of mind are also properties of body. This leaves it open whether the mind and body may share some accidental or non-defining properties. Finally, there is an even weaker kind of dualism which we may call property dualism. According to this view, there are mental properties which are distinct from and irreducible to bodily properties.4 However, these mental properties may or not be properties of an underlying substance that also has bodily properties. In other words, the same thing may have both mental and bodily properties, so having mental properties is not enough to make something a different kind of substance.
Johansen, Thomas Kjeller (2017). Aristotle on the logos of the craftsman. Phronesis. ISSN 0031-8868. 62, p. 97–135. doi: 10.1163/15685284-12341321. Full text in Research Archive Show summary
Aristotle thinks that an account, a logos, of some sort is characteristic of craft, technē. Some scholars think that the logos element of technē is tagged onto experience as a theoretical element not directly engaged in successful production: I argue instead that the logos grounds the productive ability of craft, and also that is practically orientated in a way that distinguishes it from the logos of theoretical science. Understanding the logos of craft thus helps us explain how the craftsman differs both from the merely experienced practitioner and from the theoretical scientist.
Johansen, Thomas Kjeller (2016). 'Natural bodies in Plato and Aristotle'. In Buchheim, Thomas & Meissner, David (Ed.), Soma. Körperkonzepte und körperliche Existenz in der antiken Philosophie und Literatur. Felix Meiner Verlag. ISSN 9783787329298. p. 455–470. Full text in Research Archive
Johansen, Thomas Kjeller (2016). ‘Parmenides’ Likely Story’. Oxford Studies in Ancient Philosophy (OSAP). ISSN 0265-7651. 50, p. 1–29. Full text in Research Archive
Johansen, Thomas Kjeller (2016). ’Gud som verdens årsag: Timaios og Lovene 10’. In Larsen, Jens Kristian & Fink, Jakob Leth (Ed.), Platon - værk og virkning. Gyldendal Akademisk. ISSN 9788702112559. p. 332–342. Full text in Research Archive
Johansen, Thomas Kjeller (2015). The two kinds of end in Aristotle: The view from the de Anima'. In Ebrey, David (Eds.), Theory and Practice in Aristotle's Natural Science. Cambridge University Press. ISSN 9781107295155. p. 119–136. doi: 10.1017/cbo9781107295155.007. Full text in Research Archive
Johansen, Thomas Kjeller (2015). ‘A triptych in Plato’s Timaeus. A note on the receptacle passage (Timaeus 48e-52d)’. Classical Quarterly. ISSN 0009-8388. 65, p. 885–886. Full text in Research Archive
Johansen, Thomas Kjeller (2014). 'Why the Cosmos Needs a Craftsman: Plato, Timaeus 27d5-29b1'. Phronesis. ISSN 0031-8868. 59, p. 297–320. doi: 10.1163/15685284-12341270. Full text in Research Archive
Johansen, Thomas Kjeller (2014). Parts in Aristotle’s Definition of Soul: De Anima Books I and II. In Corcilius, Klaus & Perler, Dominik (Ed.), Partitioning the Soul. Debates from Plato to Leibniz. De Gruyter Brill. ISSN 9783110311808. p. 39–62. doi: 10.1515/9783110311884.39. Full text in Research Archive
Johansen, Thomas Kjeller (2013). 'Timaeus in the Cave'. In Gill, Christopher; Boys-Stones, George & Murr, Dimitri El (Ed.), The Platonic Art of Philosophy. Cambridge University Press. ISSN 9781316629505. p. 90–109. doi: 10.1017/cbo9781139856010.007. Full text in Research Archive
Johansen, Thomas Kjeller (2012). ’Capacity and Potentiality: The Perspective of Aristotle’s De Anima’. Topoi. ISSN 0167-7411. 31(2), p. 209–220. Full text in Research Archive
Johansen, Thomas Kjeller (2010). 'Should Aristotle have recognised final causation in Plato's Timaeus?'. In Mohr, Richard (Eds.), One Book, The Whole Universe: Plato's Timaeus Today. Parmenides Publishing. ISSN 9781930972322. p. 179–200. Full text in Research Archive
Johansen, Thomas Kjeller (2009). 'From Plato's Timaeus to Aristotle's De Caelo: The Case of the Missing World Soul'. In Bowen, Alan & Wildberg, Christian (Ed.), New Perspectives on Aristotle's De Caelo. De Gruyter Brill. ISSN 9789004173767. p. 9–29. Full text in Research Archive
Johansen, Thomas Kjeller (2008). 'The Timaeus on the Principles of Cosmology'. In Fine, Gail (Eds.), The Oxford Handbook of Plato. Oxford University Press. ISSN 9780195182903. p. 463–482. Full text in Research Archive
Johansen, Thomas Kjeller (2007). ‘In Defense of Inner Sense: Aristotle on perceiving that one perceives’. In Cleary, John J. & Gurtler, Gary (Ed.), Proceedings of the Boston Area Colloquium in Ancient Philosophy. De Gruyter Brill. ISSN 9789004160491. p. 235–276. Full text in Research Archive
Johansen, Thomas Kjeller (2007). 'The soul as an inner principle of change: the basis of Aristotle's psychological naturalism'. In Scott, Dominic (Eds.), Maieusis. Essays in Ancient Philosophy in Honour of Myles Burnyeat. Oxford University Press. ISSN 9780199289974. p. 276–300. Full text in Research Archive
Johansen, Thomas Kjeller (2006). ‘What’s New in the De Sensu? The Place of the De Sensu in Aristotle’s Psychology’. In King, Richard (Eds.), Common to Body and Soul. De Gruyter Brill. ISSN 9783110183337. p. 140–164. Full text in Research Archive
Johansen, Thomas Kjeller (2003). 'Teleology and Craftsmanship in Plato's Timaeus'. In Natali, Carlo & Masi, Stafano (Ed.), Plato Physicus. Cosmologia e antropologia nel Timeo. Adolf M. Hakkert. ISSN 9789025611736. p. 65–82. Full text in Research Archive
Johansen, Thomas Kjeller (2002). 'Imprinted on the Mind: active and passive in Aristotle's theory of sense-perception'. In Saunders, Barbara & Brakel, Jaap van (Ed.), Theories, Technologies, Instrumentalities of Colour. University Press of America. ISSN 9780761822653. p. 169–188. Full text in Research Archive
Johansen, Thomas Kjeller (2002). 'Myth and Logos in Aristotle'. In Buxton, Richard (Eds.), From Myth to Reason: Studies in the Development of Greek Thought. Oxford University Press. ISSN 9780199247523. p. 279–291. Full text in Research Archive
Johansen, Thomas Kjeller (2000). 'Body, Soul and Tripartition in Plato's Timaeus'. Oxford Studies in Ancient Philosophy (OSAP). ISSN 0265-7651. 19, p. 87–111. Full text in Research Archive
Johansen, Thomas Kjeller (1998). 'Truth, Lies and History in Plato's Timaeus-Critias'. Histos. ISSN 2046-5955. 2. Full text in Research Archive
Johansen, Thomas Kjeller (1996). 'Aristotle on the Sense of Smell'. Phronesis. ISSN 0031-8868. 41, p. 1–19. Full text in Research Archive

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Johansen, Thomas Kjeller (2025). Aristotle Metaphysics Alpha and alpha. Oxford University Press. ISBN 9780198954293. 318 p. doi: https:/global.oup.com/academic/product/aristotle-metaphysics-alpha-and-alpha-9780198954293?prevNumResPerPage=20&prevSortField=1&sortField=8&resultsPerPage=20&start=0&lang=en&cc=ie. Full text in Research Archive Show summary
A translation of and commentary on the first two books of Aristotle´s Metaphysics
Johansen, Thomas Kjeller (2021). Productive Knowledge in Ancient Philosophy: The Concept of Technê. Cambridge University Press. ISBN 9781108641579. 316 p. Full text in Research Archive
Johansen, Thomas Kjeller (2012). The Powers of Aristotle´s Soul. Oxford University Press. ISBN 9780199658435. 376 p. Full text in Research Archive
Johansen, Thomas Kjeller (2004). Plato's Natural Philosophy. A Study of the Timeaus-Critias. Cambridge University Press. ISBN 9780521790673. 224 p. Full text in Research Archive
Johansen, Thomas Kjeller (1997). Aristotle on the Sense-Organs. Cambridge University Press. ISBN 9780521583381. 304 p. Full text in Research Archive

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Johansen, Thomas Kjeller (2024). ‘Self-Sufficiency and the Good Life in Plato’s Timaeus’. Full text in Research Archive
Johansen, Thomas Kjeller (2024). Self-Sufficiency and Happiness in Plato and Aristotle. Full text in Research Archive
Johansen, Thomas Kjeller (2023). Hva er det å være lykkelig? Full text in Research Archive
Johansen, Thomas Kjeller (2022). 'Er det egentlig mulig å bli lykkelig?'. Full text in Research Archive
Johansen, Thomas Kjeller (2012). S.Broadie, Nature and Divinity in Plato’s Timaeus. Notre Dame Philosophical Reviews. Full text in Research Archive
Johansen, Thomas Kjeller (2012). 'Nature', 'Timaeus-Critias’. In Press, Gerald (Eds.), A Companion to Plato. Continuum. ISSN 9780826435354. Full text in Research Archive
Johansen, Thomas Kjeller (2012). G. van Riel and P.Destrée (eds), Ancient Perspectives on Aristotle’s De Anima. Archiv für Geschichte der Philosophie. ISSN 0003-9101. 94. Full text in Research Archive
Johansen, Thomas Kjeller (2009). P. Gregoric, Aristotle on the Common Sense. Mind. ISSN 0026-4423. 118. Full text in Research Archive
Johansen, Thomas Kjeller (2006). M.R.Johnson, Aristotle on Teleology. Notre Dame Philosophical Reviews. Full text in Research Archive
Johansen, Thomas Kjeller (2003). J.Lennox, Aristotle De Partibus Animalium. The Philosophical Quarterly. ISSN 0031-8094. 53. Full text in Research Archive
Johansen, Thomas Kjeller (2003). A.Gregory, Plato’s Philosophy of Science. British Journal for the Philosophy of Science. ISSN 0007-0882. 54. Full text in Research Archive
Johansen, Thomas Kjeller (2001). T.Schirren, Aisthesis vor Platon. Eine semantisch-systematische Untersuchung zum Problem der Wahrnehmung. The Classical Review. ISSN 0009-840X. 51. Full text in Research Archive
Johansen, Thomas Kjeller (2001). R.J.Hankinson, Cause and Explanation in Ancient Greek Thought. Journal of Hellenic Studies. ISSN 0075-4269. 121. Full text in Research Archive
Johansen, Thomas Kjeller (1999). G.E.R.Lloyd, Aristotelian Explorations. Journal of Hellenic Studies. ISSN 0075-4269. 119. Full text in Research Archive
Johansen, Thomas Kjeller (1999). J.Ackrill, Essays on Plato and Aristotle. The Classical Review. ISSN 0009-840X. Full text in Research Archive
Johansen, Thomas Kjeller (1998). P. van der Eijk, Aristoteles, De Insomniis, De divinatione per somnum. Journal of Hellenic Studies. ISSN 0075-4269. 118. Full text in Research Archive
Johansen, Thomas Kjeller (1998). M.Frede and G.Striker (eds.), Rationality in Greek Thought. Journal of Hellenic Studies. ISSN 0075-4269. 118. Full text in Research Archive
Johansen, Thomas Kjeller (1995). A.Price, Mental Conflict. Cogito. ISSN 0950-8864. Full text in Research Archive

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Published Apr. 4, 2016 10:07 AM - Last modified Sep. 19, 2026 11:15 AM

Projects

Research groups

The Society for Ancient Philosophy