John Gray warns about the dangers of science that attempts to enhance human abilities. He says such knowledge can jeopardize the very things that make us human.

More than 70 years after C.S. Lewis wrote "The Abolition of Man", John Gray argues that Lewis' questions are even more relevant today than they were then. "The scientists of Lewis's generation were dissatisfied with existing humankind" he writes. "Using new techniques, they were convinced they could design a much improved version of the species".

But Gray says that while the scientific knowledge needed to remould humanity hardly existed then, it is rapidly developing at the present time.

He believes that the sciences of bioengineering and artificial intelligence carry serious risks. "If at some unknown point in the future it becomes feasible to remould ourselves according to our dreams" he writes, "the result can only be an impoverishment of the human world".

Producer: Adele Armstrong.