Complex sentence: Factual relativism (also called epistemic relativism, epistemological relativism or cognitive relativism) is a mode of reasoning where facts used to justify any claims are understood to be relative and subjective to the perspective of those proving or falsifying the proposition.
Split into simpler sentences: Factual relativism (also called epistemic relativism, epistemological relativism or cognitive relativism) is a mode of reasoning that extends relativism and subjectivism to factual matter and reason. In factual relativism the facts used to establish the truth or falsehood of any statement are understood to be relative to the perspective of those proving or falsifying the proposition.