It is commonplace to speak ill of positivism. "Is it possible that a positivist ever weeps?" the Russian philosopher Vasily Rozanov asked. "It is something as strange to imagine as a cow riding a cuirassier. ... In the secret depths of its soul, or rather, in its tough soulless hide, positivism reminds me of Puskin's lines: 'It leaves a senseless body to rot, without a thought, where'er it haps.' A philosophical mausoleum over a moribund mankind. I reject it, I refuse it! I despise it, fear it, hate it!"1 In basic agreement, when Frederich Nietzsche reproved Herbert Spen cer for having "a tin soul," he was much less emotional and philosophically more cautious. But it is probable that the antipositivism fashionable and dominant in Italian culture, especially after the start of this century, from Benedetto Croce to Guido de Ruggiero, was essentially equally factious and brusque. Now that polemical passions have cooled, it is time to take up the subject again with the dispassion due it. The term "positivism" describes a complex reality with a crucial histori cal and intellectual function. In Italian culture, thanks especially to Roberto Ardig?, or perhaps to his mental confusion, the positivist demand has long been changed from one of method to metaphysics. In other words, it has been crudely "reified," submitted to a process of absolutization that has traduced its significance. It has been made unverifiable. From that of field research it has been transferred to the level of simple doctrinal assertion. But toward the end of the last century, there were still more serious confu sions in Italy. In the name of a vaguely understood science, and only rarely applied empirical research, in the name of free thought and a cloudy evolutionism supposed to be based on positive research, there was a ten dency to equate radically diverse, and in some ways clearly incompatible worlds of thought, such as those of Darwin, Spencer, and Marx. This was the new "trinity" against which Antonio Labriola never