"I am sure that during this century people will discover how to modify both intelligence and instincts such as aggression," he says.
Hawking acknowledges that laws will be passed to control genetic engineering. But you know the problems with this world. Some people, often those with a lot of money, find laws little more than a nuisance.
Writes Hawking: "Some people won't be able to resist the temptation to improve human characteristics, such as memory, resistance to disease and length of life."
It's not hard to imagine that those people might be the ones who can afford to do so. After all, genetic engineering won't be cheap.
Which, Hawking says, will leave behind a vast group of "unimproved humans." These people, likely the majority, might be looking at a sticky end.
"Presumably, they will die out, or become unimportant," Hawking says. "Instead, there will be a race of self-designing beings who are improving at an ever-increasing rate."
I can't help thinking this description fits quite a few senior figures in Silicon Valley.
Their belief that they can improve themselves through weird diets, living on their own islands, micro-dosing, a touch of genetic engineering and, soon, inserting chips in their brains offers them a unique future.
Indeed, there already exist DIY Genetic Engineering Home Lab Kits -- yours for just $2,000 -- that begin to help the wealthy mine self-enhancing opportunities.