[The Goodness and Badness of Actions and What Reason Can Grasp Thereof]

In this regard, scholars have discussed whether the goodness and badness of acts can be known through reason, or whether actions possess no such moral quality that the intellect can perceive. The issue has been fully elaborated elsewhere, and we have already clarified the confusion that arises in this context. All are agreed that the mind can determine whether an act accords with or opposes the agent—that is, whether the act serves as a means to something he loves and enjoys, or to something he hates and finds harmful.

This much may sometimes be known by reason alone, sometimes by revelation alone, and sometimes by both together. Yet a detailed grasp of these matters, and knowledge of the ultimate outcome of actions—felicity or misery in the Hereafter—cannot be attained except through revelation. Whatever the messengers have reported about the particulars of the Last Day, and whatever they have enjoined regarding the detailed rulings of the sacred law, lies beyond the reach of human reason, just as what the messengers have conveyed concerning the specific names and attributes of God is likewise not known.