The late nineteenth century marks a period of profound redefinition in the conceptual framework concerning the body-mind relationship across both artistic and scientific disciplines. Under the influence of the positivist worldview, human behavior and mental processes came to be positioned as fields of study that could be quantitatively measured and systematically analyzed. This paradigm shift prompted a movement in the arts toward the analysis of actions observable and assessable through objective criteria. Konstantin Stanislavski, a pivotal figure who initiated a foundational transformation in early twentieth-century theatre arts, emerged from this era characterized by intensive scientific research and groundbreaking discoveries. The absence of a methodical and reproducible system in acting education and practice until then motivated him to conduct research and develop an acting methodology. Just as science follows measurable and experimental principles, Stanislavski similarly grounded his system on the scientific studies and data of his time. In this context, he treated the theatre as a laboratory, conducting practical trials of his theoretical constructs with actors and testing them before audiences. His fundamental approach centers on accessing the source of emotion. Seeking to capture truth on stage, Stanislavski posited that this could only be achieved through triggering the emotional centers located in regions of the human brain inaccessible via conscious awareness, thus allowing emotions to be expressed genuinely. This study focuses on the scientific data that served as a guiding framework and foundational basis for Stanislavski’s development of the Physical Actions method.