A philosophical theory or doctrine can legitimately be expected to offer at least some philosophical exposition — even though implicit — of the rationale of natural science (or sciences). We refer here to a possible philosophy of science so far as it can be derived from Husserl's phenomenology. By that we mean something more definite and explicit than a bare reference to the basis of science as may be spoken of in connection with any philosophy. Phenomenology proposes a systematic analysis of experience in the first hand. In that respect phenomenology should generally offer some meeting-point with the positive sciences pertaining to special fields of natural facts and events. On the other hand, being itself a presuppositionless philosophy, phenomenology can hardly be expected to present a speculative theory of science — whether of the older "natural philosophy" type or of the so-called "synoptic" type of scientific philosophy.