The development of new theoretical frameworks is inevitably accompanied by the introduction of new terms and a shift in meaning of pre-existing terms. This holds true for the emergence of philosophy itself, as is evinced by the fact that several ancient Greek terms (for example, eidos, ousia, hyle…) lost their original meaning when they were absorbed into ontology. In Husserl's own time, an influential thinker expressed his worries about the widespread occurrence of a specific kind of lexical change. Most likely, it was the fact that academics had suddenly begun to employ technical terms without respecting the boundaries between different scientific disciplines which incited Ernst Mach to dedicate a few paragraphs to the problem of language in several of his works. In one of his key books, Mach pointed out that, besides the positive gains of knowledge, the contact between different disciplines induces a transformation in their concepts ("eine Metamorphose der Begriffe"): "we are living at present in such a period of manifold connections between different domains of knowledge", and, Mach continues, the consequent "fermentation of concepts" exhibits remarkable phenomena.¹ What strikes the expert, and continues to today, is that all types of theorists employ specific concepts in a much looser way than any specialist within the field would dare to.² Precisely for this reason, according to Mach, a more precise determination of our concepts and a more careful delimitation of their range of application are to be expected from the cross-disciplinary usage of technical terms.