After his father's death, Teichmüller was forced to find work due to financial difficulties.

Teichmüller, however, found the time to complete his doctorate in Halle, receiving his degree in 1856 with a dissertation entitled Aristotelische Einteilung der Verfassungsformen (“Aristotle’s Classification of Forms of Government”).

When Werther was appointed German ambassador to Russia, Teichmüller followed his employer to Saint Petersburg.

After two years in Saint Petersburg, Teichmüller left the service of Werther and, in 1858, took a job as a teacher of Greek and German at the Gymnasium Annenkirche (the school of St. Anne's Lutheran Church).

In 1863, unable to continue his teaching career, Teichmüller began a year-and-a-half-long journey that took him to France, Spain, Greece, Italy, the Maghreb, the Levant, and Asia Minor.

Bobrov described Teichmüller as “a man who suffered a great deal of evil and injustice in his life while never having done wrong or harm to anyone.

He was a skilled and influential speaker and teacher, a kind and patient mentor.” Bobrov and Wincenty Lutosławski were among his most successful students.

[11] His doctrines have also been referred to as constituting a variant of Christian personalism that is in opposition to both positivism and evolutionism as well as traditional Platonism.

His main works of this period involved the Studien zur Geschichte der Begriffe (Studies in the History of Concepts, 1874) and Neue Studien zur Geschichte der Begriffe (New Studies in the History of Concepts, 3 volumes, 1876–1879).

Teichmüller considered it  imperative to separate consciousness, which includes feeling and action, from specific theoretical knowledge, and regarded such notions as space, time, and movement only as outwardly projected forms that are alien to reality itself and that condense inner processes into intuitions.