Very simply, to find the truth. Regardless of societal pressures, regardless of biases, regardless of desired or expected outcomes. Looking at something from the onset with a simplistic view and weighing the evidence before you before beginning to form an opinion, but also being willing to admit you are wrong if new evidence is presented because truth matters more than anything else, whether you perceive that truth to be totally fair or not. It's probably not completely possible for anyone to be that completely impartial, but I believe the goal should be to strive for that.