The present research is an attempt to draw a parallel between the scientific beliefs of L. Mechnikov as a sociologist and the events of his personal life which influenced his attitude to despotism. The author reveals and analyses Mechnikov's opinion of solidarity and its connection with the historical process. The history of the volunteer movement towards freedom and unification in Italy that Mechnikov took place in and his service in Garibaldi's troops are also described. L. Mechnikov was born on May 18, 1838 in St. Petersburg. His family was noble. He lived in Russia during his childhood and youth. Most of his life he spent in emigration. He studied at several universities, but did not graduate any of them. The reason for that was a very active character and the desire to travel. But these qualities helped him later to succeed as a geographer scientist and sociologist. He began his career as a translator, later worked as a commercial agent. At that time, he had a lot of duty-bound travelling. Of course, he wanted to be engaged in other occupations. His main hobby at the time was drawing. In order to become an artist, he left Russia at 21 and went to Venice. It is safe to say that this hobby played a major role in his life, despite the fact that he did not become a professional artist. L. Mechnikov came to Italy in 1860. It was the year when Garibaldi and his famous ''Thousand'' landed in Sicily and conquered Palermo. Among other members of Giovanni Nicotera's volunteer detachment Mechnikov joined Garibaldi's forces. He served in a division under General Milbiz. One of the most important tasks L. Mechnikov had to do during his service was to direct the course of fortification construction near Santa Maria. Garibaldi himself later appreciated the importance of this work, he also noted how complicated the position of the Redshirts was at this section of the front. He also participated in the battle of Volturno and was wounded. Having been released from hospital Mechnikov retired and wrote memoirs about his service in Garibaldi's troops and published it in ''Russian Bulletin''. His ''Notes'' were one of the few sources based on which Russian readers could find out about these events. He also left some valuable information about the organisation of Garibaldi's forces, his generals and about Giuseppe Garibaldi himself. The article is based on the memoirs of Giuseppe Garibaldi and L. Mechnikov and on Mechnikov's essay ''Civilization and the Great Historic Rivers''.
