Editing Argument from morality (section)

===Practical reason===
[[File:Immanuel Kant portrait c1790.jpg|thumb|Portrait of Immanuel Kant, who proposed an argument for the existence of God from morality]]
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.<ref name=OppyKant>Oppy 2006, pp. 372–373</ref> Rather than proving the existence of God, Kant was attempting to demonstrate that all moral thought requires the assumption that God exists.<ref>Guyer 2006, p. 234</ref> 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.<ref name=SEPOrder/> He accepted that it is not within the power of humans to bring the ''summum bonum'' about, because we cannot ensure that virtue always leads to happiness, so there must be a higher power who has the power to create an [[afterlife]] where virtue can be rewarded by happiness.<ref name=OppyKant/>

Philosopher G. H. R. Parkinson notes a common objection to Kant's argument: that what ought to be done does not necessarily entail that it is possible. He also argues that alternative conceptions of morality exist which do not rely on the assumptions that Kant makes – he cites [[utilitarianism]] as an example which does not require the ''summum bonum''.<ref name="Parkinson">Parkinson 1988, p. 344</ref> [[Nicholas Everitt]] argues that much moral guidance is unattainable, such as the Biblical command to be Christ-like. He proposes that Kant's first two premises only [[logical consequence|entail]] that we must try to achieve the perfect good, not that it is actually attainable.<ref>Everitt 2003, p. 137</ref>