What does it mean to be human? Julian Baggini meets with scientists who aspire to take evolution into their own hands ...


Many dystopian writers have imagined worlds in which a singular "human nature" has bifurcated or splintered into a plurality of human natures. They have portrayed societies in which the genetically modified rise above their inferior, natural cousins ("Gattaca"); or different castes of human are selectively bred for accomplishing different tasks ("Brave New World"). In some cases humans from working and middle classes evolve over millennia into two different species ("The Time Machine"), or they experience a reality that is entirely virtual ("The Matrix").

These dystopias are readily imaginable only because at some level it is obvious that human nature is malleable. There is no reason in principle why creatures like ourselves might not become radically different over time. Until recently, such mutations were simply abstract possibilities, limited to the power of gods, sorcerers and novelists. But lately we have begun to consider the possibility that technology might change us more in a generation or two than evolution has done over millions of years.

We already have some technologies that alter how we think and feel. Anti-depressants and treatments for attention deficit hyperactivity disorder (ADHD) change us as much as they cure us. Students and executives are already popping drugs such as Adderall, monadafinil, donepezil and Provigil as neuroenhancers, to boost memory during exams or to maintain concentration through periods of intense work. Pharmaceutical companies are now working on the "female Viagra", designed not to correct physiological malfunction but to change the very pattern of our desires. But pretty soon any agonising over interventions like these might seem rather quaint—like worrying about the odd pothole the day before a city is bombed into oblivion. There are much bigger changes afoot.

With psychoactive drugs, prosthetics and genetic enhancement, we are already able to fashion the fabric of the self in much more radical ways than our ancestors ever could. As we learn more about how to change and enhance our brains and bodies, we are about to gain even more power over who and what we essentially are. We are moving to a time when we are no longer satisfied with trying to understand human nature; we are now moving to prescribe it.

The most energetic proponents of these changes are known as transhumanists. One of the first to use this term in its current sense is Max More, the head of Alcor, one of the world's leading providers of cryogenic services. They work to freeze dead human bodies in the hope of being able to revive them in the future, when technology is advanced enough to do so. He describes transhumanism as a school of science dedicated to advancing “the evolution of intelligent life” beyond its current human form and limitations, “guided by life-promoting principles and values.”

Transhumanists embrace our mutability as an opportunity for improvement, even if that means we may one day be replaced another superior species. An intellectual leader of the movement is Nick Bostrom, who heads the Future of Humanity Institute at Oxford University. In a remarkably matter-of-fact way, Bostrom describes to me some of the changes he anticipates and what they might mean.

One of the milder transhumanist ideas is to speed up the brain. This would be like putting a faster processor in a computer to improve its performance. But a potential byproduct of packing in more information per second would be to slow down the perceived passage of time. This is the way it is for children: every stimulus is new, so each minute is more jam-packed with information, which makes it feel like time is just dragging by. If your mind is working ten-times faster, then you are aware of ten-times more information in the moment, so time seems to pass ten-times slower.

It is impossible to imagine what life would be like after such a change. Walking a mile would feel like walking ten, eating lunch might take what seems to be three hours. Bostrom says there are ways to deal with this. "You wouldn't have to speed it up right away,” he says, referring to the human brain. “You could perhaps take small steps to modify that in ways you found desirable. You could continue to grow over years and decades, try out new capabilities."