A later visit to foreign parts (1870-1) brought him into contact with Taine, Renan, and Mill, all of whom influenced him profoundly.  In 1871 he began to lecture on literary subjects, chiefly in Copenhagen, and out of these lectures grew his ’Hovedstroemninger i det Nittende Aarhundredes Litteratur’ (Main Currents in the Literature of the Nineteenth Century), a work that in the course of about ten years extended to six volumes, and must be considered not only the author’s capital critical achievement, but also one of the greatest works of literary history and criticism that the nineteenth century has produced.  The division of the subject is as follows:—­1.  ‘Emigrant Literature’; 2.  ’The Romantic School in Germany’; 3.  ‘The Reaction in France’; 4.  ’Naturalism in England’; 5.  ‘The Romantic School in France’; 6.  ‘Young Germany.’

In spite of the growing fame that came to him from these masterly studies, Brandes felt the need of a larger audience than the Scandinavian countries could offer him, and in 1877 changed his residence from Copenhagen to Berlin, a step to which he was in part urged by the violent antagonism engendered at home by the radical and uncompromising character of many of his utterances.  It was not until 1883 that he again took up residence in his own country, upon a guarantee of four thousand kroner (about $1000) annually for ten years, secured by some of his friends, the condition being that he should give courses of public lectures in Copenhagen during that period.

Among the works not yet named, mention should be made of his volumes upon Holberg, Tegner, Kierkegaard, Ferdinand Lassalle, and the Earl of Beaconsfield.  These brilliant monographs are remarkable for their insight into the diverse types of character with which they deal, for their breadth of view, felicity of phrase, and originality of treatment.  There are also several collections of miscellaneous essays, with such titles as ‘Danske Digtere’ (Danish Poets), ‘Danske Personligheder’ (Danish Personalities), ‘Det Moderne Gjennembruds Maend’ (Men of the Modern Awakening), and ‘Udenlandske Egne og Personligheder’ (Foreign Parts and Personalities).  The latest publication of Brandes is a careful study of Shakespeare, a work of remarkable vigor, freshness, and sympathy.

As a critic, Brandes belongs distinctly to the class of those who speak with authority, and has little in common with the writers who are content to explore the recesses of their own subjectivity, and record their personal impressions of literature.  Criticism is for him a matter of science, not of opinion, and he holds it subject to a definite method and body of principles.  A few sentences from the second volume of his ‘Hovedstroemninger’ will illustrate what he conceives that method to be:—­