Since the birth of neuroscience in the 19th century, a number of physiologists have attempted to find a skeleton key to understanding the connection between the brain and mind, whether through studying the brain's weight, its structure, or inherited genes.
自現代神經科學在十九世紀誕生後，不少生理學家就試圖從大腦的重量、構造和遺傳基因，找出大腦與心智關聯的鑰匙，截至目前，仍無法解答所有奧秘。