The papers in this series of five volumes provide a snapshot of current trends in European Cognitive Science. Each of the volumes deals with problems in cognitive science from a different perspective, covering the interacting disciplines of cognitive psychology, logic and linguistics, human-computer interaction, neuroscience and artificial intelligence respectively. Linguistics is concerned with the structure and use of languages, and logic with the form and correctness of argumentation in ordinary and scientific language. The two fields are presented with respect to their role in cognitive science and artificial intelligence: How are they realised by psychological mechanisms or biological processes on the one hand or programmed or wired in machines on the other. The contributions in this volume give introductions to the state-of-the-art, emphasizing the analysis of complexity and flexibility in logic and language in the framework of classical approaches (Chapters 3, 4, 5, 7). At the same time some contributions present a broader perspective in which an integration of the formal structure with the structure of the processing systems might be possible (Chapters 2 & 6). In this context, the differences and the perspectives of the classical approaches on the one hand and of connectionist approaches on the other are compared. (Chapters 1 & 6).contributions present a broader perspective in which an integration of the formal structure with the structure of the processing systems might be possible (Chapters 2 & 6). In this context, the differences and the perspectives of the classical approaches on the one hand and of connectionist approaches on the other are compared. (Chapters 1 & 6).