It is an assumption common to many theories of rationality that all practical reasons are based on a person's given desires. I shall call any approach to practical reasons which accepts this assumption a "Humean approach". In spite of many criticisms, the Humean approach has numerous followers who take it to be the natural and inevitable view of practical reason. I will develop an argument against the Humean view aiming to explain its appeal, as well as to expose its mistake. (...) I focus on just one argument in favour of the Humean approach, which I believe can be constructed as the background idea of many Humean accounts: the argument from motivation. (shrink)