Given the data known at the time that is not such a reach. The heart beats regularly from before one is born, when the beat is bad you are in trouble and when it stops you are dead.
Even today values are set by connections to the body. Body drives that come late and you can live without are at the lowest value, those you cannot live without go from lowest to higher by how long you can live without them, and those not connected to a body part the highest and not even found among animals.
Today we know better, and are not as distant from the rest of life as was thought but we stand on the shoulders of giants, who themselves stood on the shoulders of giants, and Aristotle stands near the base.