Descartes (1641) comes to the conclusion at the end of Meditation 2 that what “I” refers to is a thinking thing. Humans in this view are essentially thinking things.
Descartes ultimately came to the conclusion that only humans have minds, other animals being mere automata. Birch et al. (2020) explain that the scientific consensus today is that non-human animals can possess consciousness (ie., that they are thinking things).
Additionally, Turing (1950) suggests we should be open to the possibility that machines can convincingly engage in behaviors which are the basis for the attribution of consciousness
and cognitive abilities in other animals.
Suppose that Descartes was wrong that all and only humans are thinking things and that, rather, other sorts of entities like non-human animals and machines could be thinking things as well.
Would this undermine theories of human nature which aspire to identify essential properties of humans and are unique to them? Would this undermine theories (like that of Machery (2008) as presented in Lewens (2012)) which aspire to identify sets of traits which are widely distributed within the human species and which are so distributed as the result of some evolutionary process?
A full answer to this question should be sure to address the following:
•What do essentialist theories of human nature amount to?
•What do nomological theories (like Machery’s) of human nature amount to?
•What are the requirements on each view for some capacity/disposition/property to constitute or
determine human nature on each of these views?