The earliest known use of the word psychologia can be traced to the long-lost late 15th century text Psichiologia de ratione animae humanae, by the Croatian theologian-humanist-poet Marko Marulic.
The English word psychology appeared two centuries later in physician Steven Blankaart's 1694 text The Physical Dictionary, concerning "Anatomy, which treats the Body, and Psychology, which treats of the Soul."
In more modern times, psychology is defined as "the science of mental life" (William James, 1890) and as a discipline whose "theoretical goal is the prediction and control of behavior" (John Watson, 1913).
As the word psychology has evolved, so too has the science supporting it. Through observation, psychoanalysis, humanism, behaviorism, and neuroscience, the attempt to untangle the ephemeral web of human mental processes and behavior has progressed across time, slowly bringing us closer to understanding ourselves.
Psychologia is another step in that endeavor.