In 1588 Gothus travelled to Germany and studied in the Rostock University for three years. He was influenced by Pierre de la Ramée (also known as Petrus Ramus) and his philosophy rather than the Lutheran scholastics.

After getting an M.A., he returned home to Uppsala in time for the Uppsala Synod in 1593 where the founding dogmas of the Swedish Lutheran Church were made final. He was appointed professor of logistics at the recently reopened, and now Lutheran focused, Uppsala University. In 1598 he re-transferred himself to the professorship in astronomy.

He was, along with some other professors, suspended from his duty in 1606, because the archbishop of 1600 had demanded the professors to sign a petition supporting the recently crowned Sigismund of Sweden. In 1606, his antagonist Duke Charles was crowned and was not too happy about this.

When a comet appeared on the sky in 1607, Laurentius declared he could interpret what this signified. The belief in astrology and the significance of heavenly signs were still strong (see, for instance, astronomer Tycho Brahe), and Laurentius was no exception. His interpretations made him important for the King, he reinstated him at the university.

A while later, he got involved in philosophical disputes with the professor in philosophy, Jonas Magni, who was an adherent of Aristotle. Laurentius's had from Ramée acquired a scepticism towards this philosophy and defended his views rigorously.

Laurentius wrote many theological and astronomical works and also published calendars. He furthermore published a thorough Ethica Christiana 1615 - 30, a work in six parts in Swedish about Lutheranism. Following this, he in 1631 wrote a summary of this work, which has been called the prime catechetical work from 17th century Sweden.

He also wrote some historical works about Swedish history.