Eugenio Coseriu was an accomplished linguist whose acknowledged expertise in the philosophy of language distinguished him from other specialists, and who was able to articulate language not only internally, linking its many registers and levels of analysis, but also externally, through a conception that interweaves language with other cognitive faculties within the general human psychology. Here is a reassessment of the „Ten Theses on Language and Meaning“ presented by Eugenio Coseriu at the Strasbourg Colloquium in 1999. These theses are a good compendium and at the same time a personal manifesto of his philosophy of language. Starting from the place of theoretical intersection that language represents between various humanistic and non-humanistic disciplines, this article analyses the relevance of each of the theses from the evidence and current developments in psycholinguistics, developmental psychology and comparative ethology. The state of the art in these fields makes it necessary to re-examine the notions of culture and categorisation underlying the theses, without compromising the enormous legacy of the great Romanian linguist.