If the contingent exists for God also, it follows that he is not the complete master of nature and the world. To say as Ibn Daud does that God made the contingent, _i. e._, made it to be contingent, sounds like a contradiction, and reminds one of the question whether God can make a stone so big that he cannot lift it himself. His proofs in favor of freedom and the contingent are partially identical with those of Judah Halevi, but in so far as he does not explicitly admit that the will may itself be influenced by prior causes he evades, to be sure, the strongest argument against him, but he does so at the expense of completeness in his analysis. Halevi is less consistent and more thorough, Ibn Daud is more consistent, because he fails to take account of real difficulties. In the final outcome of their respective analyses, Halevi maintains God's foreknowledge at the expense of absolute freedom, or rather he does not see that his admissions are fatal to the cause he endeavors to defend. Ibn Daud maintains absolute freedom and frankly sacrifices foreknowledge; though his defence of freedom is secured by blinding himself to the argument most dangerous to that doctrine. Abraham Ibn Daud concludes his "Emunah Ramah" by a discussion of ethics and the application of the principles thus discovered to the laws of the Bible. He entitles this final division of his treatise, "Medicine of the Soul," on the ground that virtue is the health of the soul as vice is its disease. In his fundamental ethical distinctions, definitions and classifications he combines Plato's psychology and the virtues based thereon with the Aristotelian doctrine of the mean, which he also applies in detail. He omits wisdom as one of the Platonic virtues and, unlike Plato for whom justice consists in a harmony of the other three virtues and has no psychological seat peculiar to it, Ibn Daud makes justice the virtue of the rational soul. The end of practical philosophy is, he says, happiness. This is attained, first, by good morals; second, by proper family life; and third, by means of correct social and political conduct.