The Demonstration of the Existence of God:
a philosphic refutation of the principles of
Atheism
Dedicated to His Eminence Giacomo Cardinal Biffi, Archbishop of Bologna
Ascension Thursday, 1997
To prove the thesis it is first necessary to explain what a philosophic demonstration is. A philosophic demonstration is a manifestation of reasons or evidence adduced in favor of a conclusion based on a reflecion on the nature of the subject examined. Now demonstration of this kind can be made in two ways: "a priori" and "a posteriori".
A demonstration "a priori" can be termed a mathematical kind of proof. It necessarily concludes and forces the assent of the reason to the conclusion, for "a priori" terms. For example, the demonstration of 1+1=2 depends absolutely upon the definition of the terms of "1" "+" "=" and "2". This is to argue from an "a priori" cause(s) to an effect.
A demonstration "a posteriori," on the other hand, proceeds from the effect to the cause(s), the effect being more certain or clearly known, the existence and or nature of its cause is concluded. For example, smoke is observed comming from a certain place, and the existence of a combustible reaction is demonstrated from this effect. Hence it follows from the nature of a philosophical demonstration "a posteriori" that any observed effect whose existence cannot be but through the postulation of the existence of a cause, demonstrates reasonably that such a cause exists.
Now it is clear that the validity of the demonstration "a posteriori" depends only on two things, namely, the existence of the effect, and the necessity of relation between cause and effect. It is also clear that such a line of argumentation does not conclude to any perfect knowledge of the essence of the cause, but merely that it does exist and has a nature sufficient to cause the effect.
Thus far, the nature of a philosophic demonstration. Now to conclude to the proof of the thesis.
I. If there is a God who is a cause of something knowable, then the existence of this God is demonstrable "a posteriori".
II. If there is a God whose essence is knowable, then the existence of this God is demonstrable "a priori".
These follow from the nature of the two kinds of philosophic demonstration. For in the first case, God is a cause of a known effect, and in the second, the nature of God is presupposed as a definition.
Examining the first case, more closely:
III. If there is an effect, the cause of which cannot be but by postulating the existence of God, then such an effect demonstrates the existence of God.
And, likewise, the second, more closely:
IV. If there is an idea of God that necessarily includes existence, then such an idea demonstrates the existence of God, necessarily.
However, the fourth statement, is argued by some to conclude only in the order of ideas of existents and not of existing-existents, and therefore is rejected by some as an invalid or insufficient.
Nevertheless, the third statement, concludes validly on the condition stated therein.
Hence, the existence of God is demonstrable by reason, if the third statment is validly demonstrated.
Since the discussion taking place here regards the question: "Wheter the existence of God can be demonstrated by reason, and if so, how?" it is uselful at this point in the discussion to examine more closely the notion of God for three reasons:
1. It is clear that the nature of God is not self-evident. For there are a multiplicity of notions of the divine among many cultures.
2. Likewise among philosphers there are those who attribute to God various names, about which there is no small disputation: the prime mover, the first cause, the world-governor, the infiinite being, the necessary being, etc..
3. Also, in recent centuries there has been no small number of individuals who assert that God is nothing more than a postulat of reason.
To address these adequately, first it must be said that it suffices to discuss the question at hand without reference to the authority of revelation of any kind, for to answer the question of the existence of God, to be demonstrable "a posteriori" by reason, there need not be an appeal to the authority of any revelation, since revelation of its very nature transcends the order of things knowable by reason alone, though not of the order of things knowable by reason in general.
Hence when discussing the question "Whether the existence of God can be demonstrated by reason, and if so, how?" it suffices to employ argumentation based on a philophical reflection of the things known by the human mind in its present state.
Now it is clear that the demonstration of conclusion cannot be had without a definition of terms, both of that from which a conclusion is adduced and that to which the conclusion concludes. For example, to demostrate that the acceleration of gravity produced by a heavenly body has certain predictable characteristics it is first necessary to define the nature of the body, of gravity, and of both the characteristics to be predicted and the units of measurement. Otherwise the demonstration cannot proceed.
Likewise in the demonstration of the existence of God it is necessary that there be an definition of terms, on which basis the demonstration is to proceed.
Now some may object that such is a "petitio principii" in the matter at hand. And this argument seems valid in the case of a demonstratoin "a priori". But that this is not the case either in a demonstration "a priori" or "a posteriori" is clear from the following considerations.
A. In a demonstration "a posteriori" the necessary definition of terms is not a "petitio principi" for the demonstration proceeds from known effect to the existence of a cause that stands in a necessary relation of causality in respect to the known effect. In such a case the definition of terms is not a "petitio principi" because the terms so defined are not principles of the demonstration but terminii, Which is not what a "petitio principii" means, viz., a begging of principles, and it is clear that a principle is "from which" and not a "to which."
B. Moreover in a demonstration "a priori" neither is the definition of terms that proceed the demonstration a "petitio principi," for what is demonstrated is an effect, which is not self evident, from a cause that is defined. This objection would hold if what was to be demonstrated "a priori" pertained to the definition of the cause in a self-evident manner, e.g. "Given: a white object: It has a color. The color is white." Yet, for this reason the demonstration "a priori" of God's existence is held to be invalid by some. This is not the case, however, for if the existence of God were self-evident, then there would be no need of demonstration, let alone of disputation thereof. For the demonstration, here specifically, is not of "Whether the most perfect existing thing does exist" but rather "Whether that which is the formal cause of the notion of perfection qua perfection does actually exist." (By the term "formal cause" the rational principle of a thing's essence or definition is signified.)
Hence it is necessary and valid to define the notion of God prior to any demonstration of God's existence.
Now proceeds the definiton of the notion of God:
It suffices to define God in any manner that is above the order of things which are caused by another.
This is clear from the following consideration.
If there is anything which is caused by another then this thing is not absolutely the cause of all things. Wherefore to such a being men do not attribute those characteristics customarily attributed to God, namely, omnipotence, omniscience, infinity in perfection, etc..And this is clear from the relation of that thing which is caused by another and that other which is its cause, for nothing is omnipotent, omniscient, or infiinite in perfection, etc.. which is caused by another, for it cannot have power, knowledge, or greater perfection before it is caused as does that other thing which caused it.
Nor is this notion of God contradictory as those who assert that God, so defined, not being caused by another, must be either without a cause or a self-caused cause, asserting, as they do, that both of which are absurd philosphically, and / or, indemonstrable in themselves.
However the notion of God as "that which is not caused by another" or "that which is its own cause" is neither absurd nor indemonstrable. It is not absurd for it is not self-contradictory; and it is not indemonstrable simply speaking, as will be shown below.
That such a notion of God as "that which is not caused by another" or "that which is its own cause" is not self-contradictory is clear from an examination of the terms of the notion. For the notion of "cause" does not contain the necessity of being "a cause in respect to itself," but only the relation of anything to anything in a certain respect. For John can be said to be the cause of his sitting down or rising, in which both him who is the cause and him in whom the effect is produced are the same. To object further in this regard, namely, that such an effect is not in the same order as the cause which causes it, would be a "petitio principii" for such a further assertion includes, self-evidently, the assertion that it is the nature of a cause to be "a cause of another and not of itself" or "a cause of another thing in another order" which is a definition of that species of "cause" which this notion of God expressely excludes.
Nevertheless, there may still be objected that such a definition of God is invalid since no such species of cause has been demonstrated to exist, which is patently a foolish objection, since the existence of such a species of cause is in fact the matter of the demonstration of the thesis "Whether God exists?" For such a principle would prohibit the definition of anything, not yet known, about which an investigation is sought.
That such a notion of God as "that which is not caused by another" or "that which is its own cause" is not indemonstrable simply speaking is also made clear from this: namely that which is to be demonstrated in the matter at hand, does not pertain to the essence of the cause but to its existence, and that therefore the demonstration of such does not proceed in the same order.
To explain this more fully:
What is to be demonstrated in the matter at hand is "Whether God exists?" and such a demonstration cannot proceed without a definition of God in some manner in which a demonstration of God's existence is possible on reason alone, that is, without the appeal to any revealed knowledge or authority. Now what is to be demonstrated in regard to this question is not the nature of God, which answers the question "What is God?", but rather the existence of God, which answers the question, "Whether God exists?" Hence what is to be proved is not what is defined, and therefore there is no "petitio principii".
Hence, it suffices to define God as that which is above the order of things which are caused by another. On this basis the demonstration of the thesis "Whether God exists, and if so, how?" can proceed.
The demonstration of God's existence now can be addressed directly:
God's existence can be demonstrated both "a priori" and "a posteriori," that is, both from the notion of what God is and from the observed order of things caused by another.
First, the demonstration "a priori:"
That there is a notion of God is undisputed, and the meaning of this notion as regards the discussion at hand has been sufficiently discussed, namely, that God is that cause above the order of things caused by another.
Now in as much as cause and the relation between cause and effect presuppose the notion of perfection, and that perfection, in its turn, presupposes a notion of gradation, it is clear that there can be no judgement of perfection in any thing unless the mind, reflecting on the relations among things known, can judge in accord with the gradation of perfection among these. But this is not possible, as Plato has amply demonstrated, unless the mind can refer itself to that which is the definition par excellence of the measure by which the mind measures. Thus in the examination of cause and effect reason must necessarily refer itself to a notion of perfection in an absolute degree. This notion of perfection without limit, self evidently includes the notion of existence, for it has never been rationally disputed that the non-existence of being qua being is to be preferred to its existence. Nor can it be, for the relation of existence to non-existence is itself bound up in the necessity of the mind to refer to a gradation of perfection, for this is what is means to make a rational judgment.
Hence there cannot be any notion of cause in any degree unless there is a notion of a most perfect existing cause. Now that this most perfect existing cause does actually exists is easily demonstrated from the following reflection: there is nothing known by reason alone unless there is first something observed. That there is a notion, then, of a most perfect existing cause, cannot be unless there is a most perfect existing cause which is a cause of the things observed by men.
Therefore God exists.
Next, the demonstration a posteriori:
There is nothing observed which does not belong to the order of things caused by another. If there were this thing, being without the cause of anything else would be God. Proof: God is that which is above the order of things caused by another. If there were more than one thing which was above the order of things caused by another, then there would have to be a common cause of both, for these would both share the notion of being without dependence on another. Which is another way of saying that what is identical in any two things has a common origin in a third thing, for unless this were true there would be nothing to cause the similarity of the two in a given respect. But "nothing" cannot be the cause of anything formally, for this would be absurd, for it does not exist to be a cause of anything. Therefore there can only be one thing in the order of things above the order of those things caused by another.
Therefore there is nothing observed which does not belong to the order of things caused by another, for if there was then this would be God and the demonstration of God's existence would be empirically verifiable, that is, by scientific experimentation..
Since therefore there is nothing observed which is not caused by another, then the demonstration can move on to an analysis of the order of causes which depend one upon another.
Among this order there can be no cause unless there is some other cause which caused it, since there is no member of this order that is not caused by another, as is plainly the case. But if there is no cause but that which is caused by another, this necessitates dependence of each cause upon one or more of other causes. And these in turn are dependent on another(s). However, since none of these causes can be without being caused by others in turn, there are only three possible cases to describe the collectivity of the causes in this order. The possibility of each will now be considered.
Regarding the order of things caused by another there are three explanations to be considered, namely:
I. That the order of things caused by another is arranged in an infinite regression of cause upon cause, so that there is neither beginning nor end of causality in this order, but only succession of prior to posterior.
II. That the order of things caused by another is arranged in a circular regression so that there is neither beginning nor end, but only the succession of former to later and later to former.
III. That the order of things caused by another is dependent upon a cause above the order of things caused by another, which is itself the cause of the first cause which is dependent on another, and which in turn initiates the order of causes which depend on another.
But I & II are indemonstrable by reason, while III is so. Hence God exists. That III is demonstrable has been proved in the first demonstration. That I & II are indemonstrable will be shown now.
The demonstration of the Indemonstrability of Thesis I:
That an infinite regression of dependence in the order of causes caused by another is not demonstrable by reason is clear from the following considerations: If there were such a regression it would not be observable in itself, for the infinite is beyond observation; furthermore, what is not observable cannot be known except via its observable effects. Hence if there is an infinite regression of dependence of cause upon cause in the order of things caused by another there must be something observable that concludes to this infinite regression, if this regression is to be demonstrable. But such a thing cannot be, for it must either be that order of things regressing to infinity or something else. If the former then the demonstration is a "petitio principii," for the assertion that the regression is infinite cannot be on the basis of an assertion that the regression is infinite. If the later then there must be something outside of the order of things caused by another which is caused by this infinite regression. But such a thing would itself be caused and hence belong to the order of things caused by another. But a thing cannot both be and not be a member of the order of things caused by another, for this is contrary to the principle of non-contradiction, which is the foundation of reason.
Hence that there is an infinite regression of causes dependent upon another is indemonstrable by reason itself.
The Demonstration of the Indemonstrability of Thesis II:
That a circular regression in the order of causes dependent on another is not demonstrable by reason is clear from the following considerations: If there any cause, in a circular order of causes, is must depend on a prior cause, and this prior cause must depend on something still prior, and the most prior on the most posterior, for this is what a circle is by definition. But since any cause in the order of things caused by another cannot be unless caused by another, by definition, there can be no cause in a circular regression of causes unless either one of two possibilities exists, namely, that all causes in this order exist simultaneously or that there is such an effect in each and every cause, as cause, to include the ability to be the cause of each and every other cause as cause.
That all such causes would necessarily have to exist simultaneously is clear. That they could exist simultaneously is self-contradictory, for if they did then the circular regression, which arises from the succession of causes, in the order of things caused by another, would itself not be caused by another. Or in other words, the order of things which depend upon another would itself be the cause of that which is not caused by another. But this is absurd. For then a thing not caused by another would itself be caused by another.
Moreover the other possibility, namely, that each and every cause in a circular order of causes, so described, would otherwise have to be the cause of such an effect as to include the ability to be the cause of every other effect. But in such a case each and every cause would be the cause of something identical to itself in a manner that would include being the cause of itself. Hence for such a circular order to exist each and every cause must be the cause of itself, but this is absurd, for such a cause would both belong and not belong to the order of things caused by another, which violates the principle of non-contradiction, which is the foundation of reason itself.
Therefore that there is a circular regression of causes in the order of things caused by another is indemonstrable by reason.
Since thesis I & II have been shown to be indemonstrable by reason, only thesis III remains a possible for rational demonstration. But for a clear exposition, this thesis will be examined more closely.
The Demonstration of the Demonstrability of Thesis III:
That in the order of things caused by another there must be at least one thing caused by that which is not caused by another, being itself not in the order of things caused by another. Which is another way of saying that the order of things caused by another must depend upon that which is not caused by another. Nor is this contradictory for it does not involve the patent absurdity that that which is caused by another is the cause of that which is not caused by another, but rather the reasonable conclusion that that which is caused by another is itself caused by something not caused by another.
Hence there is a cause of the order of things caused by another, which in itself is not observable, but which exists, this being the only rationally demonstrable explanation of the existence of the order of things caused by another.
Yet some, like Hume, dispute the existence of an order of things caused by another for they deny the existence of any relation of cause and effect. Which is a patently absurd assertion for the non-existence of any relation of cause to effect it is indemonstrable by reason. It is indemonstrable by its very nature, for to demonstrate is to manifest reasons that conclude from cause to effect or effect to cause, by the very definition of "demonstration." Therefore if such were demonstrated it would disprove the very validity of the method used to so demonstrate it. Which is the epitome of self-contradition. Therefore such a thesis is absurd; and hence cannot be.
Therefore there is such an observed order of things caused by another which depend initially on an existing cause which is above the order of things caused by another.
But that which is above the order of things caused by another is God, by the aforesaid definition.
Therefore God exists.
The following document has been released to the public domain by its author, in accord with the laws of the United States of America. This document is an extract from Theism & Atheism in Dialogue