 The act of hypothesis has two  aspects.[22]  First, hypothesis as law (Gesetz) or groundwork (Grundlegung) is the transcendental foundation for scientific experience, i.e., for the activity of legislating and thus rationally understanding the phenomena. The “phenomena” in question are not however the sensible phenomena of subjective, psychic experience (Erlebnis), but are instead themselves already constructions or interpretations. These constructions in turn are founded on hypotheses of a lower order, viz. on specific concepts formulated to transmute particular subjective experiences into objective knowledge. To take up our earlier example, when the astronomer speaks of planets and their laws of motion, he is speaking objectively of scientific phenomena, as opposed to the subjective appearance of sensible phenomena to you or me. Therefore, on Natorp’s view, strange as it may sound, the phenomenon “Mars” is an hypothesis, an object certainly, but for all that an ideal and never fully determined thought-object; moreover, the motion of this object, too, is ideal: it can be calculated with the utmost exactitude. It is these two hypotheses—the concept, “Mars”, and the laws governing its motion—that alone are objective, and susceptible to knowledge; the reddish speck in the sky is merely a subjective appearance, of which there can be no genuine (astronomical) science.