Sense perception is the ultimate authority in empiricism.
Rationalism, on the other hand, maintains that there is a special domain of knowledge acquired by means of a capacity called reason and this knowledge is inaccessible through sense perceptions. Reality transcends observable phenomena and empirically obtained knowledge is only a poor substitute for the reality obtainable by mental vision alone. In rationalism mathematics is considered the ideal form of knowledge and reason is the ultimate authority. According to the internationally known science philosopher Hans Reichenbach, rationalism is the philosophy of a man dissatisfied with sense experience and who wishes something beyond. Whether or not his criticism of rationalism as a psychological crutch of philosophers disgruntled with life is valid, his reluctance in placing ultimate authority in human reason is warranted.