Background: One of the authors' encounter with one of Sigmund Freud's original works about the anatomy of the human brain stem and his interest in the scientist, anatomist, philosopher, writer and revolutionary Georg Büchner led to re-examination and review of the original writings of two major 19th century protagonists of brain anatomy research. The aim of the authors is to highlight the achievements of both Freud and Büchner in the field of comparative brain morphology.
Methods: The medical and philosophical publications of Georg Büchner were reviewed with reference to the historical-critical edition of his complete works and writings (the so-called Marburg edition). Evaluation of the neuroanatomical achievements of Sigmund Freud was based on a summary of his publications and also partially on his autobiographical writings.
Results: After careful review of their publications both Freud and Büchner should be acknowledged as brain scientists focusing particularly on comparative morphology. Both chose fish as the subject of their macroscopic (Büchner) and microscopic (Freud) neuroanatomical studies, and both cut across their own language and cultural space by continuing their work in France. In interpreting their findings both were influenced by their respective contemporary methodological schools of thought. Büchner became a soul scientist/psychologist by turning to the writing of literary texts, heralding the end of his idealistic and metaphysical interpretation of life. Likewise, Freud increasingly devoted himself to the destiny of man and his "conditio humana," eventually turning away from anatomical brain research.
Conclusion: Review of the biographies and medical-scientific, as well as philosophical publications, of Georg Büchner and Sigmund Freud reveal striking parallels between the two researchers in addition to common insights that have generally been ignored or only marginally addressed in the past. Both should be appreciated and remembered as forerunners of today's neuroscientific community.