Final answer:
Sigmund Freud designed the first comprehensive system of constitutional psychology, presenting a theory of personality and describing psychosexual stages of development.
Step-by-step explanation:
The first comprehensive system of constitutional psychology was designed by Sigmund Freud. Freud presented the first comprehensive theory of personality, recognizing that much of our mental life takes place outside of our conscious awareness. He also proposed three components of personality and described psychosexual stages of development.