The purpose of this essay is to stimulate academic discussion about the ethical justification of using human primordial stem cells for tissue transplantation, cell replacement, and gene therapy. There are intriguing alternatives to using embryos obtained from elective abortions and in vitro fertilisation to reconstitute damaged or dysfunctional human organs. These include the expansion and transplantation of latent adult progenitor cells.

According to the standard view, the causal process connecting a past representation and its subsequent recall involves intermediary memory traces. Yet Bertrand Russell and Ludwig Wittgenstein held that since the physiological evidence for memory traces isn't quite conclusive, it is prudent to come up with an account of memory causation-referred to as nmemic causation—that manages without the stipulation of memory traces. Given mnemic causation, a past representation is directly causally active over a temporal distance. I argue that the stipulation of (...) memory traces is indeed indispensable for analyzing mernory causation. (shrink)