A culture based on reason leads to the formation of a vibrant, healthy, adaptable, wise and hopeful society, and acculturation, as a key process in the formation of individual and social identity and attitudes, plays a fundamental role in human interaction with the world around us. From the perspective of two great philosophers, Al-Farabi and Spinoza, rationality and acculturation are two related concepts but with different approaches. Al-Farabi sees rationality as a guiding force for human perfection and the realization of moral and social virtues that are strengthened in the context of culture and traditions of society. In contrast, Spinoza considers rationality to be a scientific and necessary cognition that goes beyond cultural limitations and its goal is to understand natural cause-and-effect relationships and achieve true freedom. By examining the concepts of rationality and acculturation in the thought of both philosophers, this study attempts to clarify the connection and differences between cultural rationality and actual rationality, and to show how acculturation can both facilitate and hinder the development of rationality from different philosophical perspectives. This analysis leads to a deeper understanding of the role of culture and rationality in shaping human experience and highlights the challenges in linking the two, especially in contemporary societies