If it be true that there can be no metaphysics transcending human reason, it is no less true that there can be no empirical knowledge that is not already caught and limited by the a priori structure of cognition.
C.G. Jung's work suggests that while metaphysical truths may lie beyond human understanding, the way we grasp empirical knowledge is inherently shaped by our pre-existing cognitive frameworks. This implies that our understanding of experiences is fundamentally limited by our mental constructs, which precede and guide our perceptions.
The quote highlights a critical relationship between the innate structures of our cognition and the knowledge we acquire through experience. Jung is pointing out that our reasoning capabilities fundamentally influence how we interpret and process the world around us, showing that even sensory perceptions are filtered through our cognitive predispositions.