J. Hughes over at the Institute for Ethics and Emerging Technologies blog:
Enlightenment values presume an independent self, the rational citizen and consumer who pursues her self-interests. Since Hume, however, Enlightenment empiricists have questioned the existence of a discrete, persistent self. Today, continuing that investigation, neuroscience is daily eroding the essentialist model of personal identity. Transhumanism has yet to come to grips with the radical consequences of the erosion of the liberal individualist subject for projects of enhancement and longevity. Most transhumanist thought still reflects an essentialist idea of personal identity, even as we advance projects of radical cognitive enhancement that will change every element of consciousness. How do ethics and politics change if personal identity is an arbitrary, malleable fiction?
The Enlightenment thinkers attempted to move past the idea of human nature as being defined by God-given immortal souls inhabiting flesh, to the view that we are rational minds emerging out of and transforming nature. John Locke, for instance, believed an immaterial soul was an unnecessary explanation for the self. He argued that since we are thinking matter, which is as much in God’s power to create as an immaterial soul, that it is our capacity to think which makes us ensouled persons. He considered however that this created a problem for the identity of the soul at the Resurrection of Souls at the Judgment. If consciousness resides in the body, and the resurrected body at the end of time has none of the matter of the original body, then how could you be the same person?