In that clamour which has arisen in the modern world, where now this, and then that, is demanded for and by large bodies of modern women, he who listens carefully may detect as a keynote, beneath all the clamour, a demand which may be embodied in such a cry as this: Give us labour and the training which fits for labour! We demand this, not for ourselves alone, but for the race.

Schreiner was born in Cape Town in 1890. He was the son of William Philip Schreiner, a well-known advocate, civil servant and Prime Minister of the Cape Colony, and his wife, Frances, a sister of President F. W. Reitz. The author Olive Schreiner was his aunt.He went to Rondebosch Boys' High School and then the South African College School (SACS). An excellent student, he "could have had the Rhodes Scholarship for the asking", but understood, in the light of Rhodes's involvement in the Jameson Raid and subsequent fallout with William Schreiner, that "no Schreiner took such a gift from such a man".Instead, Schreiner went up to Cambridge University to read law at Trinity College. A string of academic prizes was interrupted by the outbreak of World War I. Schreiner enlisted in the British Armed Forces, was wounded in the right arm at the Battle of the Somme, and received the Military Cross.