There’s a lively post by Uppinder Mehan over at IEET which amusingly illustrates why it is problematic to cash-out human status in terms of gross substrate similarly (two upper limbs, no claws, no spidey senses, etc. ). However, Mehan’s argument still depends on equally question-begging transhumanist assumptions about the substrate invariance of the human. Bottom line: Humans are the descendants of nonhumans and might well have nonhuman descendants. We are not yet in a position to know whether differently embodied minds or minds born of emergent AI programs will think like us or be able to co-exist with us. To think this through you need to add Speculative Posthumanism to the critical discourse of the ” Minnesota-style Posthumanities” and the normative doctrine of transhumanism.