My work is mainly within philosophical logic, in particular

• relevant logic
• substructural logic
• paraconsistent logic
• paradoxes involving self-referance
• issues connected to modal logic

Talks at peer-reviewed conferences

• Entailment or implication?: Variable Sharing Properties and Their Discontents, Troy NY, 14.-16.11.24
• The Significance of the Use Criterion: New Directions in Relevant Logic, Online, 10. & 18.11.22
• Supressing Irrelevance: Australasian Association for Logic (AAL) 2022 Conference, Online, 22.–24.06.22
• Logical Suppression Anew: Logic and Metaphysics Workshop of the Graduate Center (CUNY), New York, 25.04.22
• MaGIC and Relevance: Interdisciplinary Research in Logic, Bergen 03.12.21
• Farewell to Suppression-Freedom (Youtube): Logica Universalis Webinar, 24.03.21
• Classical Relevant Logics (slides): LanCog workshop on substructural logics, Lisbon, 26.09.19–27.09.19
• Disjunctive Syllogism in Relevant Logics (slides): Bergen Workshop on Logical Disagreements, Bergen, 28.05.19–29.05.19
• Dialetheic Paths to Triviality (slides): 4th World Congress and School on Universal Logic, Rio de Janeiro, 03.04.13–07.04.13

Public debate

• Øgaard, Tore Fjetland. 2016. Lomheims logikk. Klassekampen.

• Spring 2024: LOG111/311 - Deduction and Metalogic: lectures & seminars
• Spring 2023: LOG111/311 - Deduction and Metalogic: lectures & seminars 
• Spring 2022: LOG111/311 - Deduction and Metalogic: lectures & seminars 
• Spring 2021: LOG111/311 - Deduction and Metalogic: lectures & seminars 
• Spring 2020: LOG111/311 - Deduction and Metalogic: lectures & seminars 
• Autumn 2019: EXPHIL-MNSEM - Examen Philosophicum: seminars
• Spring 2019: LOG111/311 - Deduction and Metalogic: seminars

Academic lecture

• Øgaard, Tore Fjetland (2024). Entailment or implication?. (external link)
• Øgaard, Tore Fjetland (2022). The Significance of the Use Criterion. (external link)
• Øgaard, Tore Fjetland (2022). Suppressing Irrelevance. (external link)
• Øgaard, Tore Fjetland (2022). Logical Suppression Anew. (external link)
• Øgaard, Tore Fjetland (2021). MaGIC and Relevance. (external link)
• Øgaard, Tore Fjetland (2021). Farewell to Suppression-Freedom. (external link)
• Øgaard, Tore Fjetland (2019). Disjunctive Syllogism in Relevant Logics. (external link)
• Øgaard, Tore Fjetland (2019). Non-Boolean Classical Relevant Logics. (external link)
• Øgaard, Tore Fjetland (2013). Dialetheic Paths to Triviality. (external link)

Academic article

• Øgaard, Tore Fjetland (2024). Simplified Semantics for Further Relevant Logics II: Propositional Constants. (external link)
• Øgaard, Tore Fjetland (2024). Simplified semantics for further relevant logics I: unreduced semantics for E and Π′. (external link)
• Øgaard, Tore Fjetland (2023). The weak variable sharing property. (external link)
• Øgaard, Tore Fjetland (2023). Relevance through topical unconnectedness: Ackermann and Plumwood’s motivational ideas on entailment. (external link)
• Øgaard, Tore Fjetland (2021). From Hilbert proofs to consecutions and back. (external link)
• Øgaard, Tore Fjetland (2021). Confused Entailment. (external link)
• Øgaard, Tore Fjetland (2021). Non-Boolean classical relevant logics II: Classicality through truth-constants. (external link)
• Øgaard, Tore Fjetland (2020). Boolean negation and non-conservativity III: the Ackermann constant. (external link)
• Øgaard, Tore Fjetland (2020). Boolean negation and non-conservativity II: The variable-sharing property. (external link)
• Øgaard, Tore Fjetland (2020). Farewell to Suppression-Freedom. (external link)
• Øgaard, Tore Fjetland (2020). Boolean negation and non-conservativity I: Relevant modal logics. (external link)
• Øgaard, Tore Fjetland (2019). Non-Boolean classical relevant logics I. (external link)
• Øgaard, Tore Fjetland (2019). Substitution in Relevant Logics. (external link)
• Field, Hartry; Lederman, Harvey; Øgaard, Tore Fjetland (2017). Prospects for a naive theory of classes. (external link)
• Øgaard, Tore Fjetland (2017). Skolem Functions in Non-Classical Logics. (external link)
• Øgaard, Tore Fjetland (2016). Paths to Triviality. (external link)

Doctoral dissertation

• Øgaard, Tore Fjetland (2023). A Study in Relevant Logics. (external link)

Reader opinion piece

• Øgaard, Tore Fjetland (2016). Lomheims logikk. (external link)

See a complete overview of publications in Cristin.

_{^{The publications are arranged according to when they were first published; years in parenthesis are the issue-years (when available).}}

Accepted for publication

• Suppressing Irrelevance: Notes on Arnon Avron’s view of relevance. Logique et Analyse.

2025

• Entailment generalized. In: Sedlár, I., Standefer, S., Tedder, A. (eds) New Directions in Relevant Logic. Springer, Cham. doi: 10.1007/978-3-031-69940-5_13
• Withered relevance: evaluating the Anderson-Belnap account of relevant logics. In: Sedlár, I., Standefer, S., Tedder, A. (eds) New Directions in Relevant Logic. Springer, Cham. doi: 10.1007/978-3-031-69940-5_4
• Øgaard, T.F. (2024). Edwin Mares. The Logic of Entailment and its History. Cambridge University Press, Cambridge, UK, 2024, xv + 264 pp. The Bulletin of Symbolic Logic, 30(3), 422–424. doi: 10.1017/bsl.2024.31

2024

• Øgaard, T.F. (2024) Simplified semantics for further relevant logics I: unreduced semantics for E and Π′. Logic and Logical Philosophy. doi: 10.12775/LLP.2024.021 (Open Access)
• Øgaard, T.F. (2024) Simplified semantics for further relevant logics II: Propositional constants. Logic and Logical Philosophy. doi: 10.12775/LLP.2024.022 (Open Access)

2023

• Øgaard, T.F. (2023) A Study in Relevant Logics. Bergen: University of Bergen (dissertation).
• Øgaard, T.F. (2023). Relevance through topical unconnectedness: Ackermann and Plumwood's motivational ideas on entailment. Australasian Journal of Logic. 29(2): 154–187. doi: 10.26686/ajl.v29i2.8284 (Open Access).
• Øgaard, T.F. (2023). The weak variable sharing property. Bulletin of the Section of Logic. doi: 10.18778/0138-0680.2023.05 (Open Access).

2021

• Øgaard, T.F. (2022). Confused entailment. Topoi. 41(1): 207–219. doi: 10.1007/s11245-021-09758-x (access without subscription).
• Øgaard, T.F. (2021). From Hilbert proofs to consecutions and back. Australasian Journal of Logic. 18: 51–72. doi: 10.26686/ajl.v18i2.6770 (Open Access).
• Øgaard, T.F. (2021). Non-Boolean classical relevant logics II: Classicality through truth-constants. Synthese. 199(3–4): 6169–6201. doi: 10.1007/s11229-021-03065-z (Open Access).

2020

• Øgaard, T.F. (2020). Farewell to suppression-freedom. Logica Universalis. 14: 297–330. doi: 10.1007/s11787-020-00255-0 (Open Access).
• Øgaard, T.F. (2021). Boolean negation and non-conservativity I: Relevant modal logics. Logic Journal of the IGPL. 29(3), 340–362. doi: 10.1093/jigpal/jzaa019 (access without subscription).
• Øgaard, T.F. (2021). Boolean negation and non-conservativity II: The variable sharing property. Logic Journal of the IGPL. 29(3), 363–369. doi: 10.1093/jigpal/jzaa020 (access without subscription).
• Øgaard, T.F. (2021). Boolean negation and non-conservativity III: The Ackermann constant. Logic Journal of the IGPL. 29(3), 370–384. doi: 10.1093/jigpal/jzaa021 (access without subscription).

2019

• Øgaard, T.F. (2021). Non-Boolean classical relevant logics I. Synthese. 198(8): 6993–7024. doi: 10.1007/s11229-019-02507-z (access without subscription).
• Øgaard, T.F. (2020). Substitution in relevant logics. Review of Symbolic Logic, 13(3), 655-680. doi: 10.1017/S1755020319000467 (access without subscription).

2017

• Field, H.; Lederman, H.; Øgaard, T.F. (2017). Prospects for a naive theory of classes. Notre Dame Journal of Formal Logic. 58: 461–506. doi: 10.1215/00294527-2017-0010 (access without subscription).
• Øgaard, T.F. (2017). Skolem functions in non-classical logics. Australasian Journal of Logic. 14: 181–225. doi: 10.26686/ajl.v14i1.4031 (Open Access).

2015

• Øgaard, T.F. (2016). Paths to triviality. Journal of Philosophical Logic. 45: 237–276. doi: 10.1007/s10992-015-9374-6 (access without subscription).