In 1808, he published an epoch-making book, "Über die Sprache und Weisheit der Indier" (On the Language and Wisdom of India). Here he advanced his ideas about religion and importantly argued that a people originating from India were the founders of the first European civilizations. Schlegel compared Sanskrit with Latin, Greek, Persian and German, noting many similarities in vocabulary and grammar. The assertion of the common features of these languages is now generally accepted, albeit with significant revisions. There is less agreement about the geographic region where these precursors settled, although the Out-of-India model has generally become discredited.