and conclude with the existence of God. Some of these arguments propose moral facts which they claim evident through human experience, arguing that God is the best explanation for these. Other versions describe some end which humans should strive to attain that is only possible if God exists. Many arguments from morality are based on moral normativity, which suggests that objective moral truths exist and require God's existence to give them authority. Often, they consider that morality seems to be binding – obligations are seen to convey more than just a preference, but imply that the obligation will stand, regardless of other factors or interests. For morality to be binding, God must exist. In its most general form, the argument from moral normativity is: A human experience of morality is observed. God is the best or only explanation for this moral experience. Therefore, God exists. Some arguments from moral order suggest that morality is based on rationality and that this can only be the case if there is a moral order in the universe. The arguments propose that only the existence of God as orthodoxly conceived could support the existence of moral order in the universe, so God must exist. Alternative arguments from moral order have proposed that we have an obligation to attain the perfect good of both happiness and moral virtue. They attest that whatever we are obliged to do must be possible, and achieving the perfect good of both happiness and moral virtue is only possible if a natural moral order exists. A natural moral order requires the existence of God as orthodoxly conceived, so God must exist. Variations Practical reason In his Critique of Pure Reason, German philosopher Immanuel Kant stated that no successful argument for God's existence arises from reason alone. In his Critique of Practical Reason he went on to argue that, despite the failure of these arguments, morality requires that God's existence is assumed, owing to practical reason. Rather than proving the existence of God, Kant was attempting to demonstrate that all moral thought requires the assumption that God exists. Kant argued that humans are obliged to bring about the summum bonum: the two central aims of moral virtue and happiness, where happiness arises out of virtue. As ought implies can, Kant argued, it must be possible for the summum bonum to be achieved. He accepted that it is not within the power