Ender studied at the Stella Matutina Jesuit college in Feldkirch from 1888 to 1896. After matriculation in 1896 he studied at the universities of Innsbruck, Vienna, Prague and Freiburg. In 1901 he received his doctorate from the University of Innsbruck. In 1901-02, he completed a legal internship year at the district court Feldkirch. From 1902 to 1908 he was articled clerk in Feldkirch and Vienna. In 1908 he opened his own law firm in Bregenz. The same year he married Maria Rusch. Thery had four sons and three daughters.