Lotze recognizes the futility of thought if the sense data as data are final, if they alone are real, the truly existent, self-justificatory and valid. He sees that, if the empiricist were right in his assumption as to the real worth of the given data, thinking would be a ridiculous pretender, either toilfully and poorly doing over again what needs no doing, or making a wilful departure from truth. He realizes that thought is evoked because it is needed; and that it has a work to do which is not merely formal, but which effects a modification of the subject-matter of experience. Consequently he assumes a thought-in-itself, with certain forms and modes of action of its own, a realm of meaning possessed of a directive and normative worth of its own--the root-fallacy of rationalism. His attempted compromise between the two turns out to be based on the assumption of the indefensible ideas of both--the notion of an independent matter given to thought, on one side, and of an independent worth or force of thought-forms, on the other. This pointing out of inconsistencies becomes stale and unprofitable save as we bring them back into connection with their root-origin--the erection of distinctions that are genetic and historic, and working or instrumental divisions of labor, into rigid and ready-made structural differences of reality. Lotze clearly recognizes that thought's nature is dependent upon its aim, its aim upon its problem, and this upon the situation in which it finds its incentive and excuse. Its work is cut out for it. It does not what it would, but what it must. As Lotze puts it, "Logic has to do with thought, not as it would be under hypothetical conditions, but as it is" (I, 33), and this statement is made in explicit combination with statements to the effect that the peculiarity of the material of thought conditions its activity. Similarly he says, in a passage already referred to: "The possibility and the success of thought's production in general depends upon this original constitution and organization of the whole world of ideas, a constitution which, though not necessary in thought, is all the more necessary to make thought possible."[31] As we have seen, the essential nature of conception, judgment, and inference is dependent upon peculiarities of the propounded material, they being forms dependent for their significance upon the stage of organization in which they begin.