Abstract
This paper is an attempt to improve the practical argument for beliefs in God. Some theists, most famously Kant and William James, called our attention to a particular set of beliefs, the Jamesian-type beliefs, which are justified by virtue of their practical significance, and these theists tried to justify theistic beliefs on the exact same ground. I argue, contra the Jamesian tradition, that theistic beliefs are different from the Jamesian-type beliefs and thus cannot be justified on the same ground. I also argue that the practical argument, as it stands, faces a problem of self-defeat. I then construct a new practical argument that avoids both problems. According to this new argument, theistic beliefs are rational to accept because such beliefs best supply us with motivation strong enough to carry out demanding moral tasks