For the philosopher, bias is generally engaged through metaphysical discourse and an investigation of 'what is objectivity' through the lenses of epistemology, ontology, and axiology, which is to say, how a thinker conceives of bias itself in questions of knowledge, existence, and value.
Bias, Normativity, and Objectivity
It is arguable that judgment itself is bias, depending on one's views on objectivity and normativity. As a person who believes knowledge and truth are constructed from the existence and agency of embodied intelligence (SEP), I, like others, hold that values perforate every aspect of information, from language to ethical preference. This of course can be a disputed notion, since what constitutes agency and free will, intelligence, and normativity are themselves open to discussion and debate. Some hold that objectivity is simply a part of intersubjectivity. In the philosophy of science, theory-ladeness suggests, if true, that our linguistic expressions of our realities are unalterably contaminated by our conceptual theoretical presuppositions.
Also, questions of cognitive biases, for instance, which are of great interest in the philosophy of mind and psychology demonstrate there seems to be systematic neurological biases when dealing with information. Behavioral economists like Kahneman, Tversky, and Ariely rail heavily on how the philosophical notion of Homo economicus is a myth in the face of empirical evidence. Just like the lungs show teleological bias (SEP) in their behavior, so too does the brain. What has come out naturalized epistemology is the idea that our knowledge isn't simply understood as true or false, and that traditional philosophical notions of semantic theories of truth themselves are biased towards rationality that takes a lot of logical and mathematical training to arrive at.
Understanding and Overcoming Bias
The first step to dealing with bias is to define it. What is bias? Here, it can be seen that implicit and explicit biases exist in various domains of discourse. Implicit bias such as racial profiling is a question for ethics and social justice. Cognitive bias is a question for psychology. Biases in IQ tests. In rhetoric, there can be biases inherent in word use, such as loaded language. In logic, popular informal fallacies show that reasoning can be biased. And of course, media bias has half a dozen recognized forms (FAIR.org).
To overcome bias requires among other things:
In short, there is no royal road to defeating bias, but rather pursuing a life dedicated to the study of reason, philosophy, and science. Of course, in English, we have a short-hand term for this: critical thinking. This is an idea that is rooted in Western philosophy with claims like "The unexamined life is not worth living.". There certainly is no shortage of challenges to our knowledge, such as the defeasibility of reason, lies, propaganda, illusion, delusion, and apathy. But though knowledge may be inherently fallible, it's Philosophy with a capital P that is constantly seeking to understand, define, and expose bias, which unfortunately for Socrates led to a rather noble, but painful end.