[ladon86]

It’s pretty surprising that they believed this. The heart is very obviously thumping in your chest, and it’s very easy to notice that the (visible) veins in your wrists, neck and thighs are pulsing at the same rate.

It just seems like a more obvious “center” for an ancient person; the mechanics are so easily detectable from the outside, while the liver sits silently.

[some_random]

I think that's at least partially a view that's obvious because we now consider the heart the "center" of the body. The lungs are obviously expanding as you breath, your stomach obviously digests your food into what becomes you, blows to the head cause mental issues so it's obvious that the brain is used to think.

Meanwhile there's this huge organ in your chest with a non-obvious purpose, I don't think it's that unreasonable for someone to claim it holds your soul or something.

[__MatrixMan__]

Agreed. We put the things we want to believe, but don't have evidence for, in places where we have the least evidence lying around to contradict them. It's why there's a woo woo subculture that uses words like "quantum" in dubious ways.

[asveikau]

Not only that but the heart rate changes with your breathing, physical activity, thoughts, emotions ... I want to say it "has the pulse" but that sounds like a corny literal use of the expression.