[6] By the end of that year, Karl was sent to study Classical economics in Berlin and Paris, and this, paired with his recent and lingering illness, quashed what little energy he had to pursue his scientific interests.

Karl eventually completed an apprenticeship with the Disconto-Gesellschaft, after which he traveled and worked in various banks in America, London and Paris.

He embrced his role in civil society, undertaking board memberships at various organizations and wading into the world of art.

[4] Beginning in 1907, Karl was the founding chairman of the Art Association (Kunstverein) of Kassel, and under his leadership, the Avant-garde movement was first introduced to that city.

[9] It was one of the last holdouts in Kassel, but by 1930, the firm had been acquired by Deutsche Bank, of whose Cassel bureau Karl Pfeiffer would be president of until 1934.

The government took advantage of a vacation trip to Madeira to promote Nazi functionary Rudolf Braun to the chairmanship in Pfeiffer's absence.

In 1935, to add insult to injury, Pfeiffer was removed from his position at the head of the Kunstverein and classified by the Nazi government as an "undesirable (unerwünschte) person.

He also continued to travel extensively, to Italy, Spain, Egypt, Algeria, Tunisia, the Balkans and the Dodecanese and Canary Islands.

[15] This renewed interest in the natural sciences, paired with his loss of position due to the rise of the Nazi Party, meant that Karl had more time than he knew what to do with, so in 1937 he embarked on a months-long collection trip to East Africa, out of which the majority of his taxonomic work would come, and in 1939 a second collection trip to Java and the East Indies.