Cézanne was an innovative post-impressionist painter, and quite a troubled man. Tirelessly craving a better understanding of nature, he was constantly a la recherche. Every aspect of his lifestyle reflected his desire to achieve that objective: spending most of his time alone (away from his wife Hortense and son Paul), renting rooms or buying shelters in the middle of nature in the South of France, being self critical to the point of meditating for hours in between brush strokes, etc. As a result of living on the edge, he became quite psychologically unstable, pessimistic, and full of doubt in his late sixties. His inner conflicts reflected on his art, and this can be examined through comparison with works of contemporary impressionist artist Monet, Northern-Renaissance artist Bosch, and Dutch period painter Rembrandt.
The Inscrutable is thought to have been painted between 1898 and 1900. Historians mention some correlation between some physiological aspects of Cézanne's face and a photograph taken in Aix around that time[Josse Bernheim-Jeune]. His thin eyebrows make him look slightly oriental here, which is in keeping with his modus operandi. When looking at previous portraits it appears that Cézanne always paid careful attention when depicting eyebrows; yet his face is still seen as a whole, in the post-impressionist sense. His global expression is reserved - an accurate description, since he was a quiet and polite gentleman. His landlord, "M. Couton," (a peasant), when he was renting a room down the hill of "Mont Sainte-Croix," described him as a pleasant company roommate usually engaged in conversation at the end of the day. However, he had a terrible hot temper when he was painting; therefore, he appreciated being alone when practicing his art. On that matter, history reveals some similarities with his contemporary impressionist colleague Claude Monet: both were hard workers - working early and braving Nature no matter what the weather was -, sometimes choleric, and quite often discouraged.