Humans have two kinds of beliefs, intuitive beliefs and reflective beliefs. Intuitive beliefs are a most fundamental category of cognition, defined in the architecture of the mind. They are formulated in an intuitive mental lexicon. Humans are also capable of entertaining an indefinite variety of higher-order or "reflective" propositional attitudes, many of which are of a credal sort. Reasons to hold "reflective beliefs" are provided by other beliefs that describe the source of the reflective belief as reliable, or that provide (...) explicit arguments in favour of the reflective belief. The mental lexicon of reflective beliefs includes not only intuitive, but also reflective concepts. (shrink)