As to their bodies and souls (in the sense of sentiency), the first humans arose by "natural" evolution from ancestral primate forms.

Perhaps to understand this intriguing and deeply significant aspect of the FL experience, we can see such separation metaphorically as a "linguistic death," a passage that opens a sensitive hiatus between known and unknown where the consciousness can find itself on the edge of gaining or losing, in a cognitive sense, some levels of sentiency. The adoption of the motif of death is in line with the existential philosophies that will be later mentioned that often see the limit of death as cornerstone for any systematic reflection.

In 1997, the government banned experiments on great apes, gorillas, chim- panzees, bonobos, orang-utans, on the basis that their suffering could not be justified as their level of sentiency was considered too great.

The origins of these we do not in any fundamental sense understand, other sets of laws and constants having equal a priori probability, except that they would not permit the emergence of sentiency.

Concepts of sentiency, pain perception and our 'exploitation' of animals should be at the heart of any new policy.

In general, however, the more advanced the gestation, the more likely it is that significant moral factors are introduced, such as the onset of fetal brain activity (at about 8 weeks), and of fetal sentiency (probably during the second trimester).[9]