Debes edited the Norwegian Labour Party publication Det 20de Århundre in the early 1910s, but joined the Social Democratic Labour Party of Norway after the party split in 1921. From 1925 he chaired the organization Norsk forening for sosialt arbeid. He was a judge in Oslo City Court from 1926, and published several books
In 1945 he chaired the commission that delivered a controversial document on "war children" to the Norwegian Ministry of Social Affairs, which was stopped by Sven Oftedal and never reached the Parliament of Norway for deliberation.