God is the Same as his Essence

In the Aristotelian thought of St. Thomas Aquinas, essence is synonymous with nature and substance. Therefore this teaching holds that God’s nature (his Godhead) is exactly who he is: there is nothing added to the substance of God. Whereas all living things have a substance (the primary mode of being) and accidents (the secondary modes of being), God is only a substance.

This teaching may be confusing to those who are unfamiliar with the philosophic terminology of Aristotle and Aquinas. Essentially, Aristotle held that all created beings are defined not by their constituent parts (such as atoms) but by substance. Substance is the nature of the being. Additionally, all created beings have accidents which inhere in the substance. An accident is a secondary mode of being which involves change. Typical accidental modes of being are quantity, quality (such as color, texture etc), action, posture, time, state and relation to something else. In this sense we can say that a man is composed of a substance (humanity) and a list of accidents which make him a unique person (such as height, weight, color, position, time of existence, etc.). In this light, we can see that the phrase, "God is the same as his essence" implies that God has no accidental modes of being and is defined only by his substance (his Godhead).

This teaching is not a defined dogma of Catholicism, but rather a speculative theological teaching of St. Thomas Aquinas. However, since this teaching is drawn from the dogma of God’s simplicity is at least a Sententia Communis doctine.

Not Applicable.

Primary Argument:

P1. Things of matter and form must have a nature and a suppositum which differ because other qualities are predicated to the suppositum e.g. a man has the nature of humanity plus brown skin, plus a particular height etc.
P2. God is incorporeal and has no form or matter.
C1. Therefore, God’s nature and suppositum must be equal.
P3. A being is his suppositum.
C2. Thus, God is his nature.


1) The nature of God is the Godhead and it is said to be in God. Therefore, God is not the same as his nature

Reply: Our finite intellects require us to speak of simple things as though they are composite, so we speak of God as having parts (i.e. the Trinity). In reality, God is entirely simple.

2) In created things agents have a nature and a suppositum (e.g. humanity and a man) where suppositum possesses a nature but not vice versa. Since the effect is assimilated to its cause, this must mean that created beings (the effect) are analogous to the cause (God). Therefore, God is not the same as his Godhead.

Reply: The effects of God do not imitate him perfectly. This is because a perfectly simple being like God can only be represented by many things. Therefore, an imperfection exists in created effects of God and composition is accidental to their substance. Thus the analogy between man’s nature and God’s nature does not hold.

--S.M. Miranda

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