Fakhr Razi has spelled out some features and various divisions for happiness. Occasionally, he uses this word rather than the words such as pleasure and perfection. He believes that concepts such as happiness, perfection, pleasure, etc. may not be defined palpably because they are basically improvisational, abstract and unessential. Since pleasure and perfection have an intense relationship with happiness, utilizing the above concepts could be useful. As it is known by him, happiness has levels and degrees and it has also been treated with skepticism. It has some divisions including: spiritual, physical, and external ones. He sees the mundane happiness in the perfection of theoretical and practical powers of the human soul while achieving supreme mystical state of Divine obedience and the greatest degree of happiness, from his viewpoint, is visiting God in hereafter life which leads to the hereafter and eternal salvation. For him, the greatest degree of happiness will be achieved in hereafter life.