Trust no one, question everything, do your own research, consult multiple sources, get the facts. But be prepared to accept facts that disagree with what you believe.
In general, it appears, most people do not like to question their assumptions, do research, or read things they know they are likely to disagree with, but doing those things is the price of intellectual honesty.
We need to make a conscious effort to read things we think we are going to disagree with. We have to admit to the fact that we are not always right and even somebody we disagree with a lot may have an idea that's better than ours.
Objectivity is a hard thing and we have to exercise it. We need to examine our own ideas continuously to make sure that we are right and not doing something stupid.