A Connoisseur of Uncertainty

In the early twentieth century, psychologists began exploring a new frontier—a science of subjective experience that would link body and mind in systematic ways. Advocates of this emerging science, whatever theory they espoused, strained for complete illumination of hidden depths. The ambition itself was not novel: mystics in many traditions had sought union with the deity in contemplative practice; Calvinists and Pietists had encouraged constant scrutiny of the soul for evidence of salvation or damnation. What was new in the early twentieth century was the belief that emotional depths could be measured or at least described with scientific precision. The project animated professional strategies for the systematic understanding of mental life and its connections with physical life. Everyone agreed that mind and body were linked; the question was how. Did mind influence body, or the other way around? Or did the two realms interact in subtler ways?