Its Evolution Baby
The evolutionary dream, the end point of human desire, the ability to leave behind the limitations of the Earth and take to the stars, is fraught with it's own limitations. Pohl speculates that, while a hostile environment may kill a person, we can survive because we take a bit of a friendly environment with us. We can take air, food, water and fuel to the Antartic, the Moon, Mars and beyond but the environment remains hostile and the human body, fragile and ill adapted. "Man Plus", as may be evident from the title, is concerned with the possibilities of adapting the human body and how the body itself is tied up with notions of identity and belonging.
The cyborg is familiar at least to Science Fiction readers and has been for many years, so, to most of these veterans, Pohl's ideas may seem rehashed, even clumsy in this age of genetic manipulation. Leaving aside these anachronisms (the book was written in 1976), we see in "Man Plus", the raw power of the cyborg as a work of imagination. This power manifests itself in the predominantly earthbound text in the emotional responses, clinical discourses, whispered asides and outright revulsion of those around the cyborg. Political intrigue as the project is kept from view, as well as carnivalesque musings on cyborg sexuality thicken the texture of Pohl's writing.
The counterpoint to the inhumanity of the cyborg is his superhuman abilities and his adeptness once in the right environment. After the death of the original cyborg, Roger Torraway goes through the intimate manipulations of surgeons as all his organs are removed or bypassed, a computer is attached to his back and "wings" containing solar receptors are installed. His life on Earth becomes miserable as the "monster" becomes estranged from his wife and friends by his grotesque appearance but, like the robot in the Asimov short story "Stranger in Paradise," is so ideally suited to the Martian environment that his life there is filled with the joy of belonging. The solar wings transform from demons' to angels' wings in this environment.
This is both a deeply personal look at the transformation of Torroway from man to cyborg and a socio-political reflection on the contingencies of the space race. The growing threat of nuclear armageddon and the sense of overcrowding and paranoia that this engenders on earth also formed the internal logic of the race to the moon. The inevitability of nuclear aggression is dealt with here (and during the cold war) as a force of nature rather than as a result of human actions. Dealt with in this way, it becomes a generic "threat to humanity" and we could almost read this, from a contemporary viewpoint, as the threat of ecological armageddon. It is the clock against which the "free world" is racing to start a Mars colony and the best computer predictions grant them a few years at most. Between the lines, there is room to question the inhumanity of a humanity unable to address its problems without some outside impetus such as the threat of war or ecological disaster or the illusion of same....
The emotional journey we take with Torroway is as pot-hole ridden and treacherous as it is full of hope and freedom. The freedom that exists in the absense of armies and nuclear arms. The relief of escape from the maddening political situation on Earth is accompanied by the discovery of a personal feeling of belonging by Torroway.
A twist at the end of tale seems to indicate that the plot had a former life as a short story but also initiates(?) an idea that has grasped many a Science Fiction imagination since. (No spoilers here).