One of the most important problems of philosophy is the “critical problem”, the problem of bridge between the human mind and the world, the external reality. It is the question of relations between the subject and the object. The interesting solution for this problem is given by Bernard Lonergan SJ (1904–1984), one of the most important Catholic English-speaking thinkers of the twentieth century. It would be difficult to point to someone who influenced the American Catholic philosophy and theology from the inside out more than he did: that is why he is called the “American Rahner „. He tries to connect the great tradition of Thomism and Augustinianism and, on the other hand, classical and modern philosophy, German idealism and English Empiricism. At the heart of his thinking is the theory of the human mind. With the help of transcendental and phenomenological methods, Lonergan demonstrates that the mental structure of man consists of five levels: the empirical level, the intellectual level, the rational level, the responsible level and the level of religious experience, which together create a cumulative process that leads to knowledge and decision. The most important point here is he act of understanding, the insight, which always has a creative moment, especially on the second and third levels, as an effect of the subject’s work. The correct understanding of this moment enables a mediation between the empirical, rational and idealistic understanding of the knowledge process. Correct action on all levels, faithfulness to the nature of the subject, leads to truth – according to Lonergan’s very apt maxim: objectivity is the fruit of the authentic subjectivity.