Speaking of hearts, the
Zephyrs baseball team had a robot pitcher, who was banned for the lack of a heartbeat. Having a pump installed, he was reinstated as pitcher; however, the confusion between the physical and metaphorical heart resulted in him lacking the 'heart' to strike out those batters, & the Zephyrs soon became extinct.
So, why did I mention that? Good question!
Anyway, with respect to robots, hearts are obviously metaphoric references to human qualities such as compassion, love, & other emotions, including fear. However, just because a given robot lacks one or more of those qualities, does not mean that the robot is heartless.
Souls, are a different matter, though. In the Bible, 'soul' really means 'breath' & hence, life. However, when the Israelis lost their sovereignity, the promised land was no longer much of an attraction, & so, they eventually adopted a belief in life after death, paradise, etc. "Hell' likewise was redefined. Its original meaning was "the grave" & it was a metaphor for burial in the ground. The Hebrew words were entirely different, the original word meant just that. However, they eventually used "gehenna," which meant "the valley of the son of Hinnom" where child sacrifices were offered because trash was burned and fear of legal reprisals was minimal because of the stench of the burning trash.