Critique of Pure Reason

Naturally brains are made for survival, and culture is embedded in nature. So first of all there is a natural reason why a brain exists. The cultural reason merely follows. It is a followup reason, thus not the natural reaosn as the original reason. So cultural phenomenons like philosophy and science are not the primary reason why a brain exists. In other words: Our brains were not primarily but merely secondarily made for philosophy or science or other cultural phenomenons, and philosophy or science or other cultural phenomenons are no organs of our body but merely cultural phenomenons.