Surah 7:179
"Certainly We have created for Gehenna many of the jinn and humans: they have hearts, but they do not understand with them; they have eyes, but they do not see with them; they have ears, but they do not hear with them. Those (people) are like cattle – No! They are (even) farther astray! Those – they are the oblivious."
The Heart as the Organ of Thinking
The Qur'an literally identifies the physical heart inside the chest as the biological organ that thinks, reasons, and understands ('have they not hearts wherewith to understand'). This reflects the ancient biological misconception held by Middle Eastern and Greek cultures before the neuroscience of the brain was discovered.