On 21 June 2012, during his visit to Opole University, Professor Graham Priest of Melbourne University delivered the lecture under the title Contradiction and the Structure of Unity. The meeting with Prof. G. Priest, prepared by the Opole Group of Logic, Language and Information, was held in the Plafond Room of Collegium Maius.
At the beginning, Professor Urszula Wybraniec-Skardowska welcomed the Guest and participants of the meeting. Then, Professor Janusz Czelakowski presented the scientific silhouette of the lecturer of the day. After the opening part, Professor Graham Priest delivered his lecture.
The presented concept of the part and the wholeness assumes that there exist objects which are bound in wholes through gluons. The currently existing solutions, however, lead to do regressus ad infinitum. Professor Priest's concept consists in accepting paraconsistent logic and the assumption that gluons are and are not objects. It does not lead to a contradiction (overfill) on the paraconsistent ground. The lecture aroused a lively and multi-theme discussion. Since the basic categories of Prof. Priest's theory are built over the set theory, the questions concerned the status of the very paraconsistent logic itself, as well as the role of the set theory in the theory of the part and the wholeness. One can accept here either the standard ZF Zermelo-Fraenkel theory, yet together with the binding paraconsistent logic, or the paraconsistent ZF variant with the full axiom of comprehension.
There were many questions asked with reference to Prof. Graham Priest's theory in the context of achievements of the Polish philosophy and logic, especially represented by Twardowski and Leśniewski. Also a number of questions were raised in the context of research work conducted by computer scientists, members of the GLLI, in the area of Association Model of Data Basis and Skeleton System of Semantic Knowledge Basis. In view of the great interest in the problem area and the very lecture itself, Prof. Graham Priest was asked to maintain a further scientific contact in order to exchange experience and ideas. The Professor kindly agreed, which will hopefully contribute to fruitful cooperation and successful development of joint scientific projects in the future.
The meeting was concluded. A short sightseeing tour of Opole was arranged, followed by an unofficial meeting with a close circle of participants, in which the discussion was continued.