The series, founded in 1970, publishes works which either combine studies in the history of philosophy with a systematic approach or bring together systematic studies with reconstructions from the history of philosophy. Monographs are published in English as well as in German.

In the present-day philosophy of mind, the abilities to reflect and to relate thinking to reality are subsumed under the heading of "intentionality". After an introduction to the questions and difficulties of the most relevant theories of intentionality, Stefan Kappner presents Charles Sanders Peirce's semiotic theory. He uses the semiotic concepts developed to gain systematic access to the skills of intentionality - by presenting a novel understanding of them as skills of interpreting signs. Taking constructive issue with present-day attempts at naturalisation, in particular with teleosemantics, Kappner constructs a theory of intentionality points up its biological roots, without reducing it to these.