Vaniver’s answer covers instrumental rationality. That is probably the easiest way to persuade the average person that rationality is worth considering.
However, for some people, improving their models of the word is its own reward. If this is true for one, then epistemic rationality may appeal as much as instrumental rationality, if not more.
This requires a particular viewpoint on curiosity. If you are only looking for a rush of understanding, then mysticism may be just as effective. This requires you to value not just the [simplicity? wideness?] of your model but also its truth. One possible motivation for this value could be that true models are both interesting and useful, while false models are only interesting. (That is, a complex goal system [one with many subgoals] is more likely to produce this kind of outward desire.)
Vaniver’s answer covers instrumental rationality. That is probably the easiest way to persuade the average person that rationality is worth considering.
However, for some people, improving their models of the word is its own reward. If this is true for one, then epistemic rationality may appeal as much as instrumental rationality, if not more.
This requires a particular viewpoint on curiosity. If you are only looking for a rush of understanding, then mysticism may be just as effective. This requires you to value not just the [simplicity? wideness?] of your model but also its truth. One possible motivation for this value could be that true models are both interesting and useful, while false models are only interesting. (That is, a complex goal system [one with many subgoals] is more likely to produce this kind of outward desire.)