We have now completed in outline Saadia's system of Judaism. There are many details which we necessarily had to leave out, especially in the more dogmatic part of his work, that dealing with specific Jewish doctrines, which he constructs on the basis of Rabbinical literature and Biblical allusions interpreted so as to harmonize with the statements of the Rabbis. Many questions specifically theological and eschatological assumed importance in his mind by reason of his surroundings. I mean the Mohammedan schools and sects, and the Karaite discussions which were closely modelled after them. The most important part of his system philosophically is that which deals with creation and the attributes of God. His discussions of the soul and of free will are less thorough, and the details of his doctrines of resurrection, future reward and punishment, the redemption of Israel and the Messiah are almost purely dogmatic. For a scientific ethic there is no room at all in the body of his work. A man's conduct is prescribed for him in the divine commandments, though in a general way the reason sees the right and the wrong of the so-called rational group of laws. Still as an after thought Saadia added a chapter to the "Emunot ve-Deot" in which he attempts to give a psychological basis for human conduct. Noting the various tendencies of individuals and sects in his environment to extremes in human behavior, some to asceticism, some to self-indulgence, be it the lust of love or of power, he lays emphasis on the inadequacy of any one pursuit for the demands of man's complex nature, and recommends a harmonious blending of all things for which men strive.[79] God alone, he says, is a real unity, everything else is by the very reason of its being a creature essentially not one and simple, but composite and complex. So man has a love and desire for many things, and also aversion for many things. And as in other objects in nature it takes a combination of several elements to constitute a given thing, so in man it is by a proper systematization of his likes and dislikes that he can reach perfection of character and morals. It cannot be that God intended man to pursue one object all his life to the exclusion of all others, for in that case he would have implanted only one desire in man instead of many. You cannot build a house of stones alone neither can you develop a perfect character by one pursuit and one interest.