What is the meaning and grammatical structure of the bolded sentence?
In the final paragraphs of the Philosophical Investigations, Wittgenstein characterizes psychology as consisting of empirical methods and "conceptual confusion." The methods of psychology appear to provide it with a rigorous means for answering questions about the nature of psychological processes, but problem and methods "pass one another by" (PI, p. 232 e). This situation, and not the fact that psychology is a young science, explains the "barrenness" of psychology. Wittgenstein foresaw that such conceptual confusion could be clarified through an investigation into the character of psychological concepts as such. The beginning of such an investigation was carried out in his remarks published together in the volume entitled Zettel and in the two-volume collection entitled Remarks on the philosophy of psychology.