Abstract: This research studies moral principles, ethics and life from the point of view of scientists and then investigates the role of ethic in rational life. Literally, ethics means the inner characteristics and technically it signifies the set of ingrained habits and spiritual qualities. These habits are presumed to be achieved through practice and perseverance. Ethics discusses qualities that constitute human character as well as qualities that drive him away from humanity. Life, on the other hand, means to be alive literally, however, in practice different scholars have unfolded it differently. What is understood from all definitions is that all scientists agree on its existence and accept its outcomes such as to be purposeful, procreation, etc. There are 2 kinds of life: one is the pure natural life that human beings practice to survive and the other is the rational life, which refers to conscious activities which, through volition, guides deterministic and semi-deterministic forces of natural life, along with the existence. Ethics is also of 2 dimensions: pure natural ethics and evolutionary ethics, the latter being put forward in rational life. Evolutionary ethic is human being’s awareness of necessities and merits that take place on the way of love for evolution. By expressing the compulsory natural life and evolutionary life and comparing the 2 as well as describing the evolutionary ethic and also, through integrating the ethics and rational life, this research is to pave the way for ethical development and flowering that is considered by Islam. And to the writer, this very case is distinction between the present research and the previous ones.