Fournier advanced the doctrine of the syphilitic origin of tabes, a hypothesis which was opposed for a time.

Fournier, one of the greatest syphilologists, did more than any other person to develop the knowledge regarding congenital syphilis. Through his writings, the importance of syphilis as a cause of degenerative diseases was recognized.

Fournier, great French venereologist, introduced the concept of “parasyphilis”. He showed statistically the causal relationship of syphilis to paresis and tabes.