 After attending Cleveland Street Intermediate and Sydney Boys High schools on a bursary, he studied economics at the University of Sydney and then at Teachers' College, beginning his teaching career at Bondi Public School in 1921.He also joined the New South Wales Public School Teachers' Federation in 1921; posted to various state schools, he was sent to Narrabri in 1925 and campaigned for Jack Lang, attributing his subsequent posting at Atholwood near the border with Queensland as a reaction to his political activities.Lewis returned to university part-time in 1929, teaching at Maroubra, and was a founding member and secretary of the Educational Workers' League, which advocated the abolition of public examinations, weekly tests, homework and corporal punishment.