EN
M. Heller analyses rationality in philosophy and theology of science. Philosophical reflection upon the scientific method lets perceive rationality in it understood as an effective tool of knowing and understanding the world. This possibility is conditioned by a certain structure of both a knowing subject and an object being known. Moreover, theological reflection concerning the successes of science indicates the source of rational structure of the world, which is God’s creative plan. The postulate of rationality is based on the choice of value. Thus it is a moral decision.