Skip to main content

Reason, Use of


Reason is an individual's possession of a capacity to employ his thinking and volitional powers here and now in the direction and control of his behavior in such a way that his actions can be accounted truly human and morally imputable. It thus differs from the age of reason, or the time in life when a person becomes more or less stably capable of moral judgment.

No doubt consciousness of any kind in a human being involves some operation on the part of his intellect and will, as well (in his earthly mode of existence) as of his sensory powers. But only when these several principles of activity are sufficiently sound in their separate and combined functions to enable a man to formulate a reasonable judgment concerning an end to be pursued (appraised from the point of view of ultimate human values), or the means suitable to its attainment, can he be said to enjoy the "use" of reason, i.e., the capacity to employ it freely in the pursuit of objectives specifically human in their value. If the function of his powers is impeded or impaired in such a way that he is incapable of judgment of this kind, although reason and its associated powers may be operative, a man does not possess the free use of them to human purposes and his actions cannot, therefore be classified either as perfectly human or as perfectly moral.

The use of reason may be lacking or impaired by a variety of defects. The most radical of these is an insufficiency in the development of the power of abstract thinking, or a present incapacity to exercise it, that makes a man unable to distinguish absolute from relative values and to see beyond the particular goods that appeal to his immediate desire. If this capacity is wanting, one is incapable of any truly human or moral activity whatever. Other defects may diminish one's use of reason without destroying it entirely. These may occur in consequence of malfunction of sensory perception (as in hallucinations), or of ignorance or inadvertence on the part of the mind itself, or of turbulent emotional disorder. For the influence of these defects on the use of reason and hence on moral responsibility, see ignorance; human act; voluntarity.

[p. k. meagher]

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Reason, Use of." New Catholic Encyclopedia. . 23 Mar. 2019 <>.

"Reason, Use of." New Catholic Encyclopedia. . (March 23, 2019).

"Reason, Use of." New Catholic Encyclopedia. . Retrieved March 23, 2019 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.