I think the real danger in this is that science often tries to claim that it is objective and logical. In truth, it's a human endeavor that is driven by all the biases and prejudices that humans carry with them. It's built to be error correcting so that wrong ideas are eventually overturned but that sometimes takes generations to sort out. I'd be perfectly fine with a "science of ethics" but I wouldn't be comfortable with the confidence that often comes with "science." Especially because ethics is much more slippery of a topic than most scientific subjects.
I didn't say that ethics needs to be a science, I was simply stating that a scientific (i.e. empirical) approach to ethics is not inherently a bad thing. Things such as social darwinism and eugenics and other racist/discriminatory practices are not the unavoidable conclusion of the application of science to ethics. I also don't believe that all of ethics can be treated in a scientific manner. I was simply trying to make the point that science is not the inherently dangerous element - human nature is. The problem is not that science leads to evil conclusions, its that the belief that science is perfectly objective allows people to hide their own biases (from themselves even). In truth, science is loaded with cultural/racial/gender biases that are the product of human nature but an empirical framework should eventually eliminate false conclusions. The goal of science is to gain an empirical understanding of the universe around us. If we are talking about confidence in the statistical sense, then sure we hope to gain confidence through science. If we're talking about confidence in the human sense, then it doesn't really help anyone and often gets in the way of progress. I don't really know what would be gained from a scientific approach to ethics. Maybe nothing. Or maybe it would give us a better way of understanding ethics in the context of the evolutionary "baggage" that we've accumulated. It's not exactly my field of study so I can't really say what might come of it. Lastly, I came across an interesting article on this topic as I was writing this response. I'm too new to actually post the link but it's titled "Is ethics a science?" by Massimo Pigliucci in Philosophy Now. It's not that long and worth a read if you're interested.But why does ethics need to be a science?
What are you hoping to gain from that, if not confidence?