In its 388 pages, Sommer presents a framework of ideas delving into the core of psychopathological symptoms, employing new analytical techniques and psychophysiological experiments.

He was determined to adapt and apply these methods to the field of psychopathology and develop new ones, tailored to the special purposes and objects he aimed to investigate.

[3][4] The belief that the body could be possessed by evil or domestic spirits, curses, and sin gained even greater prominence during the "Dark Ages" (as seen in the Malleus Maleficarum (1486)).

[4] When William Cullen (1710-1790) linked lunacy to nerve irritation and cerebral activity, the concept of insanity being a psychological condition gained wider acceptance.

From this, neurophysiology was formed, delving into the inner recess of the nervous system, and answering questions about how the neurons and synapses in the human body work.

[2] Sommer's work has been described as an "importance of empirical, inductive methodology for scientific development, which opposes dogmatic rigidity in systems distant from reality".

[9] However, after his publication of the "Textbook on Research Methods of Psychopathology" the book experienced rejection due to its abstraction and the dogmatic bias of the population during that time.

[10] Kurt v. Leupoldt mentions that the book contains many suggestions that would resonate more readily with contemporary readers compared to the reception it received during its original time.

[10] Sommer's engagement with psychophysiological investigation methods led him to the conception of individual reaction types, which he regarded as inherited.