by God" does not have an identical meaning to "being obligatory". This was not an objection to the truth of divine command theory, but Wainwright believed it demonstrated that the theory should not be used to formulate assertions about the meaning of obligation. Wainwright also noted that divine command theory might imply that one can only have moral knowledge if one has knowledge of God; Edward Wierenga argued that, if this is the case, the theory seems to deny atheists and agnostics moral knowledge. Hugh Storer Chandler has challenged the theory based on modal ideas of what might exist in different worlds. He suggested that, even if one accepts that being commanded by God and being morally right are the same, they may not be synonyms because they might be different in other possible worlds. Moral motivation Michael Austin has noted that divine command theory could be criticised for prompting people to be moral with impure motivations. He writes of the objection that a moral life should be sought because morality is valued, rather than to avoid punishment or receive a reward. This punishment and reward system of motivation could be seen as inadequate. Euthyphro dilemma The Euthyphro dilemma was proposed in Plato's dialogue between Socrates and Euthyphro. In the scene, Socrates and Euthyphro are discussing the nature of piety when Socrates presents the dilemma, which can be presented as the question "Is X good because God commands it, or does God command X because it is good?". The Euthyphro dilemma can elicit the response that an action is good because God commands the action, or that God commands an action because it is good. If the first is chosen, it would imply that whatever God commands must be good: even if he commanded someone to inflict suffering, then inflicting suffering must be moral. If the latter is chosen, then morality is no longer dependent on God, defeating the divine command theory. Additionally, if God is subject to an external law, he is not sovereign or omnipotent, which would challenge the orthodox conception of God. Proponents of the Euthyphro dilemma might claim that divine command theory is obviously wrong because either answer challenges the ability of God to give moral laws. William of Ockham responded to the Euthyphro Dilemma by 'biting the bullet'. He argued that, if God did command people to be cruel, then that would be morally obligatory,