>or perhaps the meaning of too many words has changed, and their context. When Hippocrates claimed that the brain was an organ to cool the blood, perhaps he meant that we use our thought to temper our emotions, i.e. what he said agrees with our modern understanding.
The belief that the heart was the seat of thought and emotion was shared by numerous cultures[0], and was based on their naive interpretation of physiology and biology and cannot be dismissed as a modern misinterpretation of a single vague aphorism by a single person due to the preponderance of documentary evidence to the contrary from contemporary sources. Also, you're probably talking about Aristotle, not Hippocrates.
>Maybe because we stopped talking about "excitable" people as being "hot-blooded"
Also people still say "hot blooded" all the time.