That's the point. Without getting into some semantic argument about what a "scientific truth" is, a "theory" is, etc, it remains that there are good social morals and rules that stand the test of time, and stand changing science.
Let science change - it always will. But don't keep twisting and turning and changing because of whatever scientific fad-of-the-day these overblown PhDs happen to be pushing today. Their God of knowledge (small "k") is fickle, indeed.
Instead, you can use a constant star as your moral compass.
Science really isn't, and shouldn't be, about morals. Science is about knowledge, the only way science should ever be applies to morals is in determining if a moral problem we're trying to solve is really a problem (for instance if global climate change is not caused by man then we have no moral duty to do anything about it, in fact we probably have a moral duty to let the planet and/ or God do whatever they want), and in determining if what we want to do about the moral problem will actually work (for instance government run anti-poverty programs never work, while we clearly have a moral duty to help the less fortunate those effort should be focused in a way that actually helps rather than ones that do nothing or in some cases actually make the problem worse).
Outside of the facts surrounding moral issues science should remain neutral. Which is exactly what Crichton is talking about, certain scientific issues have become imbued with a huge emotional/ moral/ political weight that is clouding the process. We should remove the baggage from the scientific parts of these issues and let science do what it is supposed to do: operate in a political and moral vacuum and just collect the facts and draw conclussions.