It's just a process. Find evidence, make theories. Find more evidence, adjust theories or replace them.
People gotta stop injecting their religious beliefs about "the truth" or "socialism" or whatever into science. These are just your personal beliefs and science don't give a shit about any of that.
Empirical evidence wins out in the end but... it's not that simple.
One name said a lot about this : Thomas Kuhn. Try giving The structure of scientific revolutions a read whenever you can. It's old and there are more contemporary work, but Kuhn is still a reference in epistemology.