The development of artificial intelligent systems mainly based on and imitated from human intelligence. However, there is a deviation among scholars and practitioners in artificial intelligence, philosophy and psychology realms about the essence of human intelligence and human intelligent behaviors. This paper re-looks into the issues of deviation in intelligence and intelligent behaviors, and describes the the oretical foundation and the design set forth fora proposed study to re-investigate the essence of intelligence. Inenabling a further investigation, the issues of intelligent theories,the quest of intelligence essence, the intelligent behavior andcomputation and the relationship between intelligent behaviors and artificial intelligence systems are addressed. The paper progresses to justify the investigation by discussing the nature of behavior with its respective issues that channel the discussion into intelligent processes and problem solving processes. Based on these justifications, the investigation embarks on Pragmaticism’s scientific method - a philosophical thought for “a clear idea” promoted by C. S. Peirce 1839 – 1914.