Beginning in the late 18th century and continuing through to the mid-20th century, a movement was undertaken by psychology’s pioneers to establish a mathematical basis for research modeled after the physical sciences. It is argued that this movement arose through sociopolitical pressures to legitimize psychology as an independent discipline; demarcate its disciplinary boundaries within academia; and distinguish psychology from philosophy and spiritualism. It is argued that an ahistorical view of how the quantitative paradigm gained ascendancy leaves it largely unquestioned and unchallenged within mainstream psychology. Because of this, qualitative research has endured a long and continuing struggle to gain disciplinary recognition and epistemological parity. It is proposed that despite being sidelined by decades of quantitative hegemony, qualitative research has a long history in psychology and in the last 40 years has continued to prove itself as a necessary and valuable contributor to research in psychology.