In 1896 Joseph François Felix Babinski described for the first time the phenomenon of the toes; nevertheless in this first paper he simply described extension of all toes with pricking of the sole of the foot. It was not until the second paper of 1898 that he specifically described the extension of the hallux with strong tactile stimulation (stroking) of the lateral border of the sole. Babinski probably discovered his sign by a combination of chance observation and careful re-observation and replication. He also had in mind practical applications of the sign, particularly in the differential diagnosis with hysteria and in medico-legal areas. Several of the observations and physiopathological mechanisms proposed by Babinski are still valid today, e.g, he realized since 1896 that the reflex was part of the flexor reflex synergy and observed that several patients during the first hours of an acute cerebral or spinal insult had absent extensor responses. He also found that most patients with the abnormal reflex had weakness of dorsiflexion of the toes and ankles and observed a lack of correlation between hyperactive myotatic reflexes and the presence of an upgoing hallux. He discovered that not all patients with hemiplegia or paraplegia had the sign but thought erroneously that some normal subjects could have an upgoing toe. Between 1896 and 1903 Babinski continued to think on the sign that bears his name and enrich its semiological and physiopathological value.