This study was aimed to analyze the historical, sociological and philosophical dimensions embodied in Achebe's novel, namely No Longer at Ease novel in order to point out his philosophy of life. The findings indicated that the novel is an ethnographic record of a chaotic African society in a period of social transformation from traditional tribal life to modem urban life. Besides, regarding sociological characters of the time, Achebe showed that the old African customs had been nearly or completely abandoned for the new system, and colonial education clearly had undesirable effects on African culture and society, such as economic inequality, cultural and intellectual servitude, and devaluation of traditional culture. Through the analysis of Achebe's work, his philosophy of life as a realist was revealed.