Fully-Funded PhD Position in Symbolic Explainability for Logic-Based AI Systems Vrije Universiteit Brussel (VUB) in Belgium

Vrije Universiteit Brussel (VUB) is offering a fully-funded PhD position in symbolic explainability for logic-based AI systems. The project sits in the Department of Computer Science within the Faculty of Sciences and Bioengineering Sciences, with the Brussels Humanities, Sciences & Engineering Campus in Elsene as the home base. It is a joint PhD with KU Leuven, giving the successful candidate the opportunity to work with researchers at two highly ranked universities in Belgium and the EU.

The research focus is highly relevant to current debates in explainable AI and neurosymbolic AI. While neural networks and large language models are powerful, they are often difficult to trust because of their black-box nature. Symbolic reasoning offers transparency, but its explanations can still be large and hard to interpret, especially in complex neurosymbolic settings. This PhD aims to investigate how ideas from causal reasoning and actual causation—including philosophy-inspired approaches associated with Halpern and Pearl—can improve the interpretability of logical reasoning systems. The project combines a theoretical and practical component, with the long-term goal of designing efficient algorithms that generate explanations aligned with philosophical insights about causality.

The position is ideal for candidates interested in knowledge representation and reasoning, logic-based AI, explainability, and the interface between AI and philosophy. You will join a stimulating research environment with internationally renowned groups at VUB and KU Leuven, and the project is embedded in a setting that values free research, critical thinking, and societal impact. The advertised role is a PhD-student position with a doctoral grant, not a postdoctoral appointment.

Eligibility highlights: you should have, or expect to obtain in 2026, a master’s degree in artificial intelligence, computer science, mathematics, or a related field. A strong academic record at least at cum laude level is expected. Good mathematical and programming skills are required, along with excellent English communication skills. Background in philosophy or cognitive psychology is welcomed as an advantage, and Dutch language skills are an additional asset. Applicants must also comply with VUB permit and residence requirements and must not have exceeded 12 months of paid assistant work funded from operating resources.

Funding: the university offers a full-time PhD scholarship for 12 months initially, renewable up to a maximum of 48 months subject to positive evaluation of doctoral progress. The scholarship is linked to government scales, and the effective result is subject to enrolment as a doctoral student at VUB.

Application window: applications close on 2026-09-15. Candidates should apply through the VUB jobs portal and submit a motivation letter, detailed CV, academic transcripts, diploma, names and contact details of two references, and a writing sample such as a master’s thesis.