This article explores a field of study that I call logosemantics: the theory of conceptual structures that determine philosophical expressions of ultimate insight. The kind of structures that logosemantics postulates are described with reference to the holistic philosophy of Capra. In particular the conceptualisation of holistic complexity in relation to reductionistic simplicity is thematised. In the course of this analysis the logosemantic place of complexity in the conceptual structure of philosophically foundational expressions is identified, with reference not only to Capra, but also to various philosophical "languages" in the history of Western thought, from Greek metaphysics to systems philosophy and post-structuralism. Attention is also given to some Eastern philosophies. After a purely descriptive analysis of logosemantic form, the possibility of logosemantic criticism is considered. The relation of simplicity and complexity is reviewed again, and an alternative interpretation to the one seemingly favoured by Capra is suggested.