The relationship between conscience and reason is manifested in the fact that practical reasoning (or intellect) is by itself limited to practical calculations and utilitarian evaluations, whereas conscience serves as an inner judge, calling us toward higher moral standards.

Conscience: The Supreme Moral Regulator

The relationship between conscience and reason is manifested in the fact that practical reasoning (or intellect) is by itself limited to practical calculations and utilitarian evaluations, whereas conscience serves as an inner judge, calling us toward higher moral standards. Reason may judge actions as beneficial or not, smart or foolish, but it is conscience—with its ability to distinguish absolute values—that determines what truly is good or evil. In this way, conscience functions as the supreme moral regulator, addressing us regardless of our conscious desires or selfish impulses.

As emphasized in one source, “Of course, reason alone cannot consider some actions as morally good and others as morally bad. It is prone to finding some of our or others' actions smart or foolish, expedient or inauspicious, beneficial or not beneficial” (source: link txt, page: 0). This clearly indicates that reason is incapable of independently answering the question of the moral value of actions.

Additionally, the author stresses the fundamental nature of conscience: “Conscience knows infinitely more about good and evil than our conscious ‘self’. The sources of conscience are lost in the depths of our being. Conscience is the organ of knowledge of good and evil, the organ of perceiving absolute values…” (source: link txt, page: 5). These words point out that conscience operates on a level that transcends ordinary rational judgments, which is why it is often called “the voice of Reason.” This voice is not a product of our will or personal desires; it is given to us “from above” and reminds us of the immutable moral principles that should guide our actions.

Thus, the expression “Conscience is the voice of Reason” underscores that the true understanding of good and evil, as well as the ability to make moral choices, originates not so much from the rational analysis of practical benefits, but from an inner, objective, and higher moral awareness inherent in the human being.

Supporting citation(s):
"With regard to the relationship between conscience and the human faculties of mind, will, and other feelings, we see that conscience not only tells a person what is inherently good or bad from a moral standpoint, but also obligates him to certainly do good and avoid doing evil, accompanying good actions with feelings of joy and satisfaction, and bad actions with feelings of shame, fear, and mental anguish. Of course, reason alone cannot consider some actions as morally good and others as morally bad. It is prone to finding some of our or others' actions smart or foolish, expedient or inauspicious, beneficial or not beneficial." (source: link txt, page: 0)

"Conscience knows infinitely more about good and evil than our conscious ‘self’. The sources of conscience are lost in the depths of our being. Conscience is the organ of knowledge of good and evil, the organ of perceiving absolute values. Complaints that this organ is imperfect are unfounded. Conscience never errs. However, the clear manifestation of the voice of conscience is possible only with the will to perceive that voice." (source: link txt, page: 5)