Perhaps if Nietzsche were alive today, to see the incredible advances of modern science and technology, especially modern medicine, he would have a different view of the power of science. On the other hand, we take the obvious successes of science so much for granted that people, I'm speaking of postmodernists here, don't realize the magnitude of what it has accomplished.
Contemporary physics is INCREDIBLY accurate. Quantum Field Theory is accurate beyond the wildest dreams of the science of earlier generations. Science has pegged the age of the universe, perhaps part of an infinite multiverse, at 13.72 billion years ago. Our understand of the nervous system, especially of the brain, has made enormous strides over the last few decades. We now have an impressive understanding of how the various parts of the brain are responsible for our consciousness and behavior. These two areas of understanding have provided many answers and our best shot at answering more of our deepest philosophical questions. Some questions may simply be unanswerable, or we may determine that they are ill-posed.
We are even beginning to find the parts of the brain that are active before we are aware of our intentions. Brain activity has been identified just prior to consciousness of an intention in the Libet experiments. Scientists have even been able to induce intentions by stimulating parts of the brain. This, together with my own experiences with antidepressants and anti-anxiety drugs, has convinced me that free will is an illusion. I am confident that as science progresses we will develop ever more detailed understanding of how our behavior depends on physical processes.
Those who say that Science is but the articulation of a certain technique of power are, in my opinion, all wet. I am convinced that the major scientific discoveries of the last century or so are impressively free of cultural bias. This is not by any means to say that all of the scientists themselves have been morally perfect beings, rather that the scientific enterprise is able to take the good and throw out much of the bad. As brilliant as philosophers like Foucault obviously were, everyone should read Discipline and Punish, I can only respond to their claims of the identity between scientific knowledge and power that their understanding of the hard sciences were somewhat limited. Foucault is another example of someone who could have benefited by having lived a little bit later. Foucault died of AIDS in 1984. If he were alive today more could have been done to save him, or at least prolong his life.