O cenności racjonalności w wierze religijnej

The issue of rationality of religious beliefs belongs to the main problems of 20th century philosophy of religion. When posing this problem the term `rationality' is often used in a way that is not precise, and sometimes it seems to be ambiguous. In order to avoid this error I define rationality of acceptance regulatively as a property consisting in being in accordance with defined epistemic rules of the ethics of beliefs. The main rule that is taken into consideration here is the following requirement: `Each theorem p accepted by person S should be justifiable by her in a degree proportional to the degree of assertion with which he accepts p'. Acceptances having the property of so defined rationality belong to a broader class of reasonable acts, where rationality is understood as a property consisting in being a reliable use of human cognitive abilities. I claim that although the religious faith of a `common' Christian is not rational in this sense, as mysteries of faith are not justifiable by natural reason, it has a reasonable character and is precious from the epistemic point of view. I defend the proposition that the fact of not being rational in this particular sense does not involve irrationality that consists in breaking the rule that orders a change in the way of accepting a certain theorem p so as to adjust the degree of assertion to the justification one has, the borderline case being one of rejecting the theorem for which one does not have any epistemically valid justification. The proposition that one of these rules is obligatory for the believer with respect to his acceptance of the propositions of faith cannot be justified without stating that Christianity is false. This latter proposition cannot be proved philosophically.