Several things would say that there is a very distinct possibility according to science that there is two parts. Remote viewing would be one example and Edgar Cayce's work would be another I can think of offhand.
We have no way of deciding in an absolute sense. Nevertheless, it seems we can look at it this way: in the world we inhabit and where we have to survive, we are faced with either-or situations and choices. That, of course, is dualistic. Thought, on the other hand, can transcend this apparent dichotomy and see a possibly much bigger picture. Thus, we have to live with the seeming conundrum of both a dualistic and a holistic universe. Much of humanity has a difficult time with this concept, but that doesn't mean it is not our "real" situation; i.e., that 'this/not this' (duality) and 'all-is-one' are both true for us at the same time.