The discussions of the philosophy of ethics, ethics, ethical attributes and, following it, the soul and spirit in Mulla Sadra's works are quite extensive. In fact, he has dealt with such topics in his various books and treatises in detail. He believes that the criterion for ethics is the free intellect (conscience), and human beings will be rewarded or punished in proportion to their conduct and behavior in this world. Good moral behavior in this world will indeed be compensated with good other-worldly rewards, and unpleasant behavior therein will be followed by unbearable punishment in the other world. In other words, any kind of behavior and conduct dominating Man's soul in this world will be revived in the same form on the resurrection day. Therefore, Mulla Sadra believes that self-knowledge as the receptacle of philosophy is always a way towards God and a means of attaining the knowledge of God and His attributes, which is the best of all types of knowledge in the world. That is why some of the arguments on God's existence are based on the problem of the soul. Self-knowledge is essential to the discussion of resurrection and the belief in its independence. Since some of the problems of the soul are among the ethical axioms (in spite of some disagreements among the schools of the philosophy of ethics), almost all Islamic philosophers are unanimous that ethics is related to the perfection of the soul, and that ethical discussions are based on the principle of soul's being prone to perfection and its being influenced by ethical acts. They also believe that without ethics, we will not be able to provide adequate rational and philosophical explanations for ethical good or bad.Nevertheless, in order to become aware of the quality of the perfection of the soul through ethical acts, one must know about the perfection of the soul, consider it as his purpose in life, and adopt certain ethical behaviors in order to achieve this purpose. Therefore, in Mulla Sadra's view, ethics and practical wisdom is, in fact, a kind of self-knowledge.