Contemporary data practices are inducing a convergent saturation point wherein every human action, reaction, interaction, transaction, thought or desire is quantified, reified, recorded and used. Physical or virtual, all is recorded, known or unknown, seen or unseen, until data permeates every facet of our shared human existence. The implications of this eventuality are potentially so far reaching that the very notion or concept of who we are might be fundamentally altered, resulting in new ontologies of the self in a world (...) of Total Data. This polemic paper reflects on the implications that Total Data has for the ontological self in a range of individual and shared contexts, and considers the potential it has to ultimately be symbiotic or assimilatory. It suggests that the current trajectory for Total Data is more assimilatory than symbiotic, demonstrating more potential to collectively monitor and control people than to emancipate and empower them. In response, it calls for an authentic debate and reassessment of current data practices, and for an urgent reprioritisation of core and enduring human-centred values and symbiosis in technological systems development to emancipate and empower people living in a Total Data world. (shrink)