5.1 Why a thought is invisible for Frege: Travis on the abstractedness that can be extracted from our "representing-as"—Thoughts and concepts: the "conceptual" as a referential domain, which does not possess the objectivity of the "non-conceptual"—The intermediation made by the "representing-as" as a form of judging—Travis' rejection of any internalism—Reassessing psychologism: Russell's criticism of Frege's conception of thought—Travis' suggestion of a Wittgensteinian view that takes into account the sociability of thinking. 5.2 Travis' reluctance in admitting unthought thoughts beyond the workings of language—Problems of perception: perceptive presentations and representations—The case of analogical, non-perceptive representations—Language and thought reconsidered—Frege on fictional and real thoughts: a problem of modality—The anonymous character of thought. 5.3 Aquinas and the recognition that there are truths which escape our attention—Knowing and guessing: the transcendental impossibility of representing what we do not know—Scientific predictableness—Aquinas' two kinds of intellection: "divine" and "human"—Distinction between actual and potential knowledge—The peril of determinism.