is the weak side, first of all etymologists and word-masters, and then especially of all “Indologues,” and of the whole Indian past itself. There is an enormous difference between what _can_ have been, nay, according to certain abstract theoretic views _must_ have been, and what _has_ been. That, however, is the distinctive problem for historical investigation. And here, above all, much depends on philological knowledge and sagacity; but still more on that historical tact which understands how inferences should be drawn. This demands much acquaintance with what is real, and with purely historical material; much practice, and, as regards character, much self-denial. In this _judicium subactum_ of the historian lies the difference between Niebuhr and O. Müller. To satisfy these demands, it is only necessary, with your gifts and your character, that you should wish to do so earnestly, and perseveringly wish it. Of course you will not separate the inquiry as to the oldest seat of the Sanskrit language from the surrounding problems. I am perhaps too strongly prejudiced against the idea that the family of which we are speaking must have wandered from the banks of the Upper Indus towards Bactria, and from thence founded Media and Persia. But I have for the present good grounds for this, and views which have long been tested by me. I can well imagine a migration of this family to and fro from the northern to the southern slopes of the Hindu-Kush and back again; in Egypt one sees most plainly how the Semitic, or the family which inclines towards Semitism, migrated frequently from the Mediterranean and the Euphrates to the Red Sea and _back again_. But this alters nothing in the theory, on the one hand, that it is one and the same family historically, and, on the other hand, that it is not originally African, but Asiatic. You will certainly not adopt Niebuhr’s autochthonic theory, where such facts lie before you. But enough. Only receive these remarks as a proof of my lively interest in your researches, and in yourself; and may Minerva be your guide. I rejoice in the prize you have gained at the French Academy in Paris, both for you and the Fatherland.