Phenomenal conservatism

In epistemology, phenomenal conservatism (PC) holds that it is reasonable to assume that things are as they appear, except when there are positive grounds for doubting this. (The term derives from the Greek word "phainomenon", meaning "appearance".)

The principle was initially defended by Michael Huemer in Huemer 2001, where it was formulated as follows:

  • If it seems to S as if p, then S thereby has at least prima facie justification for believing that p.

A later formulation (Huemer 2007), designed to allow the principle to encompass inferential as well as foundational justification, reads as follows:

  • If it seems to S that p, then, in the absence of defeaters, S thereby has at least some degree of justification for believing that p.