[1] Born into a family of Protestant merchants, Arntz was educated at a private academy in Düsseldorf and later attended the school of applied arts in Barmen (1921).

From the beginning of 1929 Arntz worked at the Gesellschafts- und Wirtschaftsmuseum (Social and economic museum) directed by Neurath in Vienna.

After the brief civil war in Austria in 1934 he emigrated to the Netherlands, joining Neurath and Reidemeister in The Hague, where they continued their collaboration at the International Foundation for Visual Education.

With the support of Philip Idenburg of the CBS he joined Jan van Ettinger in establishing the Dutch Foundation for Statistics in The Hague.

[5] Neurath wrote in support of Arntz's anti-fascist activity and he was eventually released in 1946 and returned to the Netherlands where Idenburg vouched for him when he was arrested as an alien.