Abstract
Sometimes an oscillation takes place between two incompatible approaches to an experienced situation: from one to another, then back and then again, and again. The oscillation is not an additional ingredient but an essential aspect of the situation. Both approaches are needed: by assuming one of them the participant is led to understand the need of the other. A process of this kind occurs in interfaith dialogue: we oscillate between considering the other religion from an objective standpoint and perceiving it from the perspective of my own religion. Some kind of oscillation is present in other situations. Several examples are given to show that the process can be seen as familiar even though it has hardly been identified as a separate phenomenon to be analyzed. According to the present author, it is related to but possibly distinct from complementarity as it is known in physics. A preliminary attempt is made to formulate the logic of the oscillation process, which can be called sequential paraclassical logic.