Abstract
Recent scholarship has challenged the Freudocentric interpretation of Carl Gustav Jung's psychology and repositioned his work within broader intellectual traditions such as William James's pragmatism. Building on this shift, this paper argues that Jung's Psychological Types (1921) constitutes not merely a work of psychology, but an implicit contribution to the philosophy of science. Specifically, it addresses the demarcation problem, understood as the question of how to distinguish scientific knowledge from non-scientific knowledge. While classical approaches sought formal criteria of demarcation, Jung reconfigures the problem by rejecting methodological monism and advancing a pluralistic framework grounded in the psychology of the knowing subject. Crucially, this pluralism is not relativistic: Jung maintains that scientific objectivity depends on the balanced integration of opposing cognitive orientations, including the subjective and objective, as well as the rational and irrational. In this framework, objectivity is not achieved through the elimination of subjectivity, but through its reflexive recognition and mediation. By situating Jung in relation to debates on intersubjectivity, theory-ladenness, and scientific pluralism, the paper demonstrates that Jung offers a distinctive account of scientific knowledge that seeks to avoid both positivist reductionism and epistemic relativism.