So humanity's power cannot continue growing indefinitely. If it reaches a high enough point, it will immediately drop to 0.
From Wikipedia: "The final chapter describes the ultimate consequences of this debunking: a distant future in which the values and morals of the majority are controlled by a small group who rule by a perfect understanding of psychology, and who in turn, being able to "see through" any system of morality that might induce them to act in a certain way, are ruled only by their own unreflected whims. The controllers will no longer be recognizably human, the controlled will be robot-like, and the Abolition of Man will have been completed."
Thanks for the tip!
"Nevertheless, I am sure that during the next century, people will discover how to modify both intelligence, and instincts like aggression."
No stopping to ponder whether removing "aggression" from humans might have some unexpected negative consequences? I find this kind of technological utopianism troubling from the likes of Kurzweil, as well. The people who debate him tend to question the feasibility of the advances he predicts. But to me the more important question is whether some of these "advances", and their possible repercussions, are even desirable.
If we think about benefit and harm, these are usually with respect to energy. It takes time to heal wounds, it takes more energy to overcome injury. Benefits, like the car for example, enable humans to expend less energy, but they take more from the environment.
If we extrapolate that to the world around us, then for example, taking a prescription drug will have a corresponding negative impact on the environment.
If what I suggest here is true, then any improvement we could make to human evolution is merely an illusion. Perhaps the improvements we do make are merely improvements, or perceived to be improvements, because we can't see the harm created somewhere else, like the destruction of landscape, deaths in mines, pollution, etc...