His attempt to submit a psychological thesis for a Brussels doctorate was blocked by Guillaume Tiberghien (1819–1901) in what became known as the Dwelshauvers affair, and Dwelshauvers only started lecturing in philosophy after Tiberghien's retirement.
In a series of articles between 1905 and 1908 Dwelshauvers criticised Henri Bergson's reliance on qualitative intuition for the study of psychological phenomena.
Introduced by August Vermeylen to the thought of Friedrich Nietzsche, he played an important role in the reception of Nietzsche in France and Belgium.
Dwelshauvers was director of a psychology laboratory in Barcelona from 1920 to 1924.