Deml studied high school in Gymnázium Třebíč where he started to publish his first works in the journal Sursum.

During the year 1897 Deml published his works in Zájmy lidu (Interest of people), and in 1899 in Nový život (New life), Dvacátý věk (Twentieth century) a Museo (Museum).

In 1905, Deml stopped publishing in Nový život (New life) and started to criticize catholic modernism and clericalism, which made him unpopular with many church representatives.

His disputes with clergy and church authorities were slowly escalating also due to the slow implementation of the Decree of Pope Pius X.

His house, designed by the famous architect Bohuslav Fuchs, served as his home until Deml's death.

In 1924 Deml in one of his speeches attacked Orel, the organization competing with Sokol and for his comments was charged with slander.

Later in life Deml stated that he valued president Tomáš Garrigue Masaryk, even though he disagreed with him on many points.

After the war Deml was accused of collaboration with the Nazis, but for lack of evidence he was let go with a small conditional penalty.