Today it is universally known that the brain is the seat of human consciousness and the organ which controls the rest of our body. However, it took our ancestors a very long time to agree on this. Many ancient scholars downplayed the importance of the strange-looking organ within our skulls.
One example of this can be found in the culture of Ancient Egypt. Namely, the Egyptians were known for their pioneering embalming techniques, which placed great emphasis on preserving the heart – it was the only internal organ left inside the mummy. This was because they considered the heart to be the center of emotion and intelligence, while all other organs were considered less important and removed. Most were placed in special canoptic jars. The brain was believed to be among the lowliest of organs, and was discarded – in fact the Egyptians didn’t even have a proper word for it!
This belief was adopted by the famous Ancient Greek philosopher Aristotle, who also considered the heart to be the seat of consciousness, in contrast to his mentor Plato, who claimed it was the brain. Aristotle believed the brain only served as a sort of radiator whose function was to “cool the passions of the heart”. He explained the human brain’s large size to be the result of humans needing large brains to cool their warm hearts. Namely, he also believed that the more complex and rational creatures produced more heat than the simpler ones (e.g. insects were among the coldest, with vertebrates being warmer, and human beings the most complex and therefore the warmest of creatures).
Many other scholars of his time shared his belief, and it was only in the time of Galen (a famous Greek physician who lived in the time of the Roman Empire) that the “heart theory” was definitely relocated to the fringe of science, though many kept believing the center of human emotions was in the heart. Even today we still use expressions like “learn by heart”, “broken heart” etc.