The character Dr Jensen, played by actor Thomas Murphy, is described as a transhumanist. He develops a mechanism for the consciousness of one person to be transferred into the body of another person. This mechanism is described as "shedding", referring to how a snake periodically sheds its skin.
The attraction of the mechanism is to continue the life of someone who is terminally ill. The transhumanist in the film remarks:
Imagine what Edison could have accomplished with another fifty years. Or Einstein. Or Steve Jobs.
It turns out that the original consciousness of the second person needs to be suppressed by regular intake of drugs. When drug intakes are missed, parts of the original consciousness start to reassess themselves, displacing parts of the new consciousness.
The original (terminally ill, but not yet dead) body of the first person is given an injection to stop its heart. This avoids any plot complication in which the same consciousness might be manifest in two different bodies at the same time.
The idea of parts of two consciousnesses inhabiting the same brain already has scientific precedence, with the observation of people with multiple personalities, including cases in which the corpus callosum joining the two hemispheres of the brain is severed .
What is less credible in this film is the idea that consciousness might be transferred from one brain to another by a machine that is described as "being like a giant magnet". If any such technology does become available in the future, many other aspects of technology and society are likely to be fundamentally altered beforehand. This is in contrast to the plot in this film, in which the "shedding" mechanism is available in a world that has very few other differences from the present day.
The transhumanist character in the film is gradually revealed to be selfish and immoral - willing to sacrifice the lives of soldiers (amongst others) to provide healthy bodies into which hyper-rich customers can transfer their consciousness.
This characteristic is implicitly contrasted with the attitude of the lead character in the film, Damian, played by actors Ben Kingsley (old body) and Ryan Reynolds (new body). Damian shows human compassion for the family of the person whose body his consciousness now occupies.
However, there should be no automatic implication that someone who develops a transhumanist technology (such as consciousness transfer) will lack human compassion or be unusually selfish.