Subjectivism (philosophy) in the context of "Credibility"

Subjectivism is the doctrine that "our own mental activity is the only unquestionable fact of our experience", instead of shared or communal, and that there is no external or objective truth.

While Thomas Hobbes was an early proponent of subjectivism, the success of this position is historically attributed to Descartes and his methodic doubt. He used it as an epistemological tool to prove the opposite (an objective world of facts independent of one's own knowledge, ergo the "Father of Modern Philosophy" inasmuch as his views underlie a scientific worldview). Subjectivism accords primacy to subjective experience as fundamental of all measure and law. In forms like solipsism, it may hold that the nature and existence of every object depends solely on someone's subjective awareness of it. One may consider the qualified empiricism of George Berkeley in this context, given his reliance on God as the prime mover of human perception.