You feel really disgusted, don't you? I can understand that. The doubt that what looks alive is actually alive... Contrarily, the doubt that things without life might be alive... The reason why dolls are creepy is that dolls are models of human, and it means they are nothing but humans themselves. The fear that humans might merely be the sum of simple clockwork tricks and substances... In other words the fear of the phenomena called "human" essentially belongs to vanity. The science that tried to explain the phenomena called "life" played a role in producing this fear. The belief that nature could be calculated leads to the conclusion that humans can be resolved into simple machinery.
"The human body is a machine which winds its own springs. It is the living image of perpetual movement." [Trans. Note: He's quoting Julien Offray de La Mettrie.]
The human-machinery theory of the 18th century... has been revived by the technology of implanting artificial brains and cyborgs. Since the time when computers made it possible to externalize the memory, in order to extend the limits of their functions as a creature, humans kept actively machinalizing themselves. It's a sign of the intention to get over the natural selection of Darwin and try to win the fights of evolutionary theory on their own. And it is also the intention to conquer the nature that created them. The illusion that life is equipped with complete hardware is the source of this nightmare itself.
"God... ever... geometrizes..." [Trans. Note: Quoting Plato.]
But things like this are pointless because we don't have all the information. Humans aren't afraid of being understood, they're afraid of being given an inadequate explanation and being told "that's it". It's a stupid fear, but it's supported by arrogance; a person wants to believe they know everything, so they will push an inadequate view as reality even when it hurts themselves.