From his youth and forwards, Bjørnson admired
Henrik Wergeland, and became a vivid spokesman for the Norwegian left-wing movement. In this respect, he supported
Ivar Aasen, and joined forces in the political struggles in the 1860s and 1870s. When the great monument over Henrik Wergeland was to be erected in 1881, it came to political struggle between left and right, and the left wing got the upper hand. Bjørnson presented the speech on behalf of Wergeland, and also honouring the constitution and the farmers. A subject which interested him greatly was the question of the , the adopting of a national language for Norway distinct from the (
Dano-Norwegian), in which most Norwegian literature had hitherto been written. At an early stage, before 1860, Bjørnson had himself experimented with at least one short story written in
landsmål. The interest, however, did not last, and he soon abandoned this enterprise altogether. Afterwards, he regretted that he never felt he gained the mastery of this language. Bjørnson's strong and sometimes rather narrow patriotism did not blind him to what he considered the fatal folly of such a proposal, and his lectures and pamphlets against the 'language strife' in its extreme form were very effective. His attitude towards this must have changed sometime after 1881, as he still spoke on behalf of the farmers at this point. Although he seems to have been supportive of
Ivar Aasen and friendly towards farmers (in the peasant novels), he later denounced this, and stated in 1899 that there was limits to a farmer's cultivation. "I can draw a line on the wall. The farmer can cultivate himself to this level, and no more", he wrote in 1899. Rumour has it that he had been insulted by a farmer at some point, and uttered the statement in sheer anger. In 1881, he spoke of the farmer's clothing borne by Henrik Wergeland, and his opinion then states that this garment, worn by Wergeland, was "of the most influential things" in the initiation of the national day. Bjørnson's attitude towards the farmers remain ambiguous. His father himself was a farmer's son. During the last twenty years of his life he wrote hundreds of articles in major European papers. He attacked the French justice in the
Dreyfus Affair, and he fought for the rights of children in Slovakia to learn their own mother tongue. "To detach children from their mother tongue is identical to tearing them away from their mothers' breasts," he wrote. Bjørnson wrote in multiple newspapers about the
Černová massacre under the title
The greatest industry of Hungary – which was supposedly "
to produce Magyars". He took part in the
sexual morality debate () of the time, arguing that free love did not allow for the development of positive traits such as self-restraint and a focus on virtue. Bjørnson held some 60 lectures in the Nordic countries on the issue; his strongly held views led to a rift with
Georg Brandes. ==Last years==