This essay focuses on the meaning that the term “experimental” acquires within spiritualism during the second half of the nineteenth century. It builds upon Paul Janet’s notions of “experience” and “experimentation” in psychology, by stressing the role of physiology and pathology in his reflection. Regardless of the role the concept of “experimentalism” took on in Victor Cousin’s psychology, which arguably indicated more an “internal affection” than actual experimentation, in Janet’s spiritualism the term regains its original meaning of empirical verification. Janet (...) highlights the importance of madness to the development of a new psychological paradigm that could reconcile philosophy and medicine, reason and experience, by taking up pathology as a form of natural and indirect experimentation. (shrink)