Skip to content
Catholic Online Logo

A term employed in scholastic philosophy to express the absolute perfection of God. In all finite beings we find actuality and potentiality , perfection and imperfection. Primary matter, which is the basis of material substance, is a pure potentiality. Moreover, change necessarily supposes a potential element, for it is a transition from a state of potentiality to a state of actuality; and material things undergo manifold changes in substance, quantity, quality, place, activity, etc. Angels, since they are pure spirits, are subject to none of the changes that depend on the material principle. Nevertheless, there is in them imperfection and potentiality. Their existence is contingent. Their actions are successive, and are distinct from the faculty of acting. The fact that all things have in themselves some potentiality warrants the conclusion that there must exist a being, God, from whom potentiality is wholly excluded, and who, therefore, is simply actuality and perfection, Actus Purus .

It is true that in the same being the state of potentiality precedes that of actuality; before being realized, a perfection must be capable of realization. But, absolutely speaking, actuality precedes potentiality. For in order to change, a thing must be acted upon, or actualized; change and potentiality presuppose, therefore, a being which is in actu . This actuality, if mixed with potentiality, presupposes another actuality, and so on, until we reach the Actus Purus . Thus the existence of movement (in scholastic terminology, motus , any change) points to the existence of a prime and immobile motor. Causality leads to the conception of God as the unproduced cause. Contingent beings require a necessary being. The limited perfection of creatures postulates the unlimited perfection of the Creator. The direction of various activities towards the realization of an order in the universe manifests a plan and a divine intelligence. When we endeavour to account ultimately for the series of phenomena in the world, it is necessary to place at the beginning of the series -- if the series be conceived as finite in duration -- or above the series -- if it be conceived as eternal-a pure actuality without which no explanation is possible. Thus at one extreme of reality we find primary matter, a pure potentiality, without any specific perfection, and having, on this account, a certain infinity (of indetermination). It needs to be completed by a substantial form, but does not of itself, demand any one form rather than another. At the other extreme is God, pure actuality, wholly determined by the very fact that He is infinite in His perfection. Between these extremes are the realities of the world, with various degrees of potentiality and actuality.

So that God is not a becoming, as in some pantheistic systems, nor a being whose infinite potentiality is gradually unfolded or evolved. But He possesses at once all perfections. He is simultaneously all that He can be, infinitely real and infinitely perfect. What we conceive as His attributes or His operations, are really identical with His essence, and His essence includes essentially His existence. For all intelligences except His own, God is incomprehensible and indefinable. The nearest approach we can make to a definition is to call Him the Actus Purus . It is the name God gives to Himself: "I am who am", i.e., I am the fullness of being and of perfection.


More Encyclopedia

The Catholic Encyclopedia is the most comprehensive resource on Catholic teaching, history, and information ever gathered in all of human history. This easy-to-search online version was originally printed in fifteen hardcopy volumes.

Catholic Encyclopedia

Designed to present its readers with the full body of Catholic teaching, the Encyclopedia contains not only precise statements of what the Church has defined, but also an impartial record of different views of acknowledged authority on all disputed questions, national, political or factional. In the determination of the truth the most recent and acknowledged scientific methods are employed, and the results of the latest research in theology, philosophy, history, apologetics, archaeology, and other sciences are given careful consideration.

No one who is interested in human history, past and present, can ignore the Catholic Church, either as an institution which has been the central figure in the civilized world for nearly two thousand years, decisively affecting its destinies, religious, literary, scientific, social and political, or as an existing power whose influence and activity extend to every part of the globe. In the past century the Church has grown both extensively and intensively among English-speaking peoples. Their living interests demand that they should have the means of informing themselves about this vast institution, which, whether they are Catholics or not, affects their fortunes and their destiny.

Copyright © Catholic Encyclopedia. Robert Appleton Company New York, NY. Volume 1: 1907; Volume 2: 1907; Volume 3: 1908; Volume 4: 1908; Volume 5: 1909; Volume 6: 1909; Volume 7: 1910; Volume 8: 1910; Volume 9: 1910; Volume 10: 1911; Volume 11: - 1911; Volume 12: - 1911; Volume 13: - 1912; Volume 14: 1912; Volume 15: 1912

Catholic Online Catholic Encyclopedia Digital version Compiled and Copyright © Catholic Online


Newsletters

Newsletter Sign Up icon

Stay up to date with the latest news, information, and special offers

Daily Readings

Reading 1, First Corinthians 12:31--13:13
31 Set your mind on the higher gifts. And now I am ... Read More

Psalm, Psalms 33:2-3, 4-5, 12, 22
2 Give thanks to Yahweh on the lyre, play for him on ... Read More

Gospel, Luke 7:31-35
31 'What comparison, then, can I find for the people ... Read More

Saint of the Day

Saint of the Day for September 17th, 2014 Image

St. Robert Bellarmine
September 17: Born at Montepulciano, Italy, October 4, 1542, St. Robert ... Read More

Inform, Inspire & Ignite Logo

Find Catholic Online on Facebook and get updates right in your live feed.

Become a fan of Catholic Online on Facebook


Follow Catholic Online on Twitter and get News and Product updates.

Follow us on Twitter