There his extraordinary judicial talent attracted attention, and on 27 July 1701 he was promoted to associate professor at the University of Halle, where he received his doctor's degree on 11 August 1702.
Four years later, on 23 May 1719, King Frederick William I of Prussia awarded him the title Geheimer Rat and nominated him on 25 May 1719 as director of the University of Halle and deputy full professor of the judicial faculty.
In the meantime and due to his good reputations he received offers from the emperor court of Wien, from the Universities of Bern, Kiel, Helmstedt, Frankfurt (Oder), Tübingen or Celle, but he disclaimed all of this, because he wanted to stay at Halle.
In the judicial field initially he was a protectionist of the existing “territorial system" or Erastian theory of ecclesiastical government, but in the following years he represented a tendency to the natural right and the “Kollegialismus” (Protestant ecclesiastical theory from the 18th century in Germany, containing the Protestant perception at that time regarding the relationship between Church and State to be understood as collegia on basis of human agreement), which was mainly continued by his sons.
A huge amount of further significant and notable works on civil and church law as well as expertises were penned by him, and were publicised by his son Georg Ludwig Böhmer after Justus Henning's death in the collected edition Exercitationes ad pandectas some years later.