The article analyses the transformations of the European science of philology in relation to the strengthening of nationalism, as well as the reflection of the trend in the context of East Prussia and Prussian Lithuania. The developments in comparative philology presupposed researchers’ interest in the studies of Baltic languages, Lithuanian in particular. The establishment of the Department of Sanskrit and Comparative Philology at Königsberg University both formed the tradition of academic Baltic studies and united the efforts of the intellectuals of East Prussia for the preservation of linguistic and ethnic-cultural heritage of Prussian Lithuania. The text Aus Baltischen Ländern by lawyer and cultural worker Ludwig Passarge is a characteristic example featuring the reflection of the ethnic-cultural model of Prussian Lithuanians against the background of predomination of comparative linguistics typical of the intellectual context of Europe in the 19th c.