' instrumental to 2 conceptual clarification of significance of physical laws, to a separation that which is empirically proven from that ich is not, to an elimination of emotional judices nurtured solely by customary views, {lit thus helps to clear the road for the onward ve of research. But Positivim lacks the driving ze for serving as a leader on this road. True, it ble to eliminate obstacles, but it cannot turn 1m into productive factors. For its activity is _ntially critical, its glance is directed backward. progress, advancement requires new associa- 1s of ideas and new queries, not based on the alts of measurements alone, but going beyond tm, and toward such things the fundamental tude of Positivism is one of aloofness. Cherefore, up to quite recently, posi hues have also put up the strongest resistance the introduction of atomic hypotheses and reby also to the acceptance of the above men- red universal constants. This is quite under- dable, for the existence of these constants is alpable proof of the existence in nature of sething real and independent of every human surement,