I disagree. What you quoted is idealistic and not realistic.
Consider, for example, this part: "IF your science makes you think some class of people mentally inferior to others... THEN you are doing it wrong."
Actually, science tells us that it is entirely possible that one class of people could be mentally inferior to others. I'm not saying that any class of humans now existing is mentally inferior to others, but I am saying that it is possible (in fact, well within the realm of possiblity) that one could be.
Whoever said what's quoted above might as well not even engage in science if he's not open-minded and willing to accept what science tells him. He would be approaching science with bias, with prejudice. He would already have his answer. Why would he need the science? What if legitimate science told him that it was possible that, for example, an isolated group of people could have smaller brains, lower neuron density, etc.? Would he just say it's bad science because he doesn't agree with what the science tells him because it's not politically correct?