E1P11S
Scholium — Part I
Latin
In hac ultima demonstratione Dei existentiam a posteriori ostendere volui ut demonstratio facilius perciperetur; non autem propterea quod ex hoc eodem fundamento Dei existentia a priori non sequatur. Nam cum posse existere potentia sit, sequitur quo plus realitatis alicujus rei naturæ competit eo plus virium a se habere ut existat adeoque Ens absolute infinitum sive Deum infinitam absolute potentiam existendi a se habere, qui propterea absolute existit. Multi tamen forsan non facile hujus demonstrationis evidentiam videre poterunt quia assueti sunt eas solummodo res contemplari quæ a causis externis fiunt et ex his quæ cito fiunt hoc est quæ facile existunt, eas etiam facile perire vident et contra eas res factu difficiliores judicant hoc est ad existendum non adeo faciles ad quas plura pertinere concipiunt. Verum ut ab his præjudiciis liberentur, non opus habeo hic ostendere qua ratione hoc enunciatum "quod cito fit cito perit" verum sit nec etiam an respectu totius naturæ omnia æque facilia sint an secus. Sed hoc tantum notare sufficit me hic non loqui de rebus quæ a causis externis fiunt sed de solis substantiis, quæ (per propositionem 6) a nulla causa externa produci possunt. Res enim quæ a causis externis fiunt, sive eæ multis partibus constent sive paucis, quicquid perfectionis sive realitatis habent, id omne virtuti causæ externæ debetur adeoque earum existentia ex sola perfectione causæ externæ, non autem suæ oritur. Contra quicquid substantia perfectionis habet, nulli causæ externæ debetur; quare ejus etiam existentia ex sola ejus natura sequi debet, quæ proinde nihil aliud est quam ejus essentia. Perfectio igitur rei existentiam non tollit sed contra ponit; imperfectio autem contra eandem tollit adeoque de nullius rei existentia certiores esse possumus quam de existentia Entis absolute infiniti seu perfecti hoc est Dei. Nam quandoquidem ejus essentia omnem imperfectionem secludit absolutamque perfectionem involvit, eo ipso omnem causam dubitandi de ipsius existentia tollit summamque de eadem certitudinem dat, quod mediocriter attendenti perspicuum fore credo.
English (Elwes 1883)
In this last proof, I have purposely shown God's existence a posteriori, so that the proof might be more easily followed, not because, from the same premises, God's existence does not follow a priori. For, as the potentiality of existence is a power, it follows that, in proportion as reality increases in the nature of a thing, so also will it increase its strength for existence. Therefore a being absolutely infinite, such as God, has from himself an absolutely infinite power of existence, and hence he does absolutely exist. Perhaps there will be many who will be unable to see the force of this proof, inasmuch as they are accustomed only to consider those things which flow from external causes. Of such things, they see that those which quickly come to pass--that is, quickly come into existence--quickly also disappear; whereas they regard as more difficult of accomplishment--that is, not so easily brought into existence--those things which they conceive as more complicated.
However, to do away with this misconception, I need not here show the measure of truth in the proverb, "What comes quickly, goes quickly," nor discuss whether, from the point of view of universal nature, all things are equally easy, or otherwise: I need only remark that I am not here speaking of things, which come to pass through causes external to themselves, but only of substances which (by Prop. vi.) cannot be produced by any external cause. Things which are produced by external causes, whether they consist of many parts or few, owe whatsoever perfection or reality they possess solely to the efficacy of their external cause; and therefore their existence arises solely from the perfection of their external cause, not from their own. Contrariwise, whatsoever perfection is possessed by substance is due to no external cause; wherefore the existence of substance must arise solely from its own nature, which is nothing else but its essence. Thus, the perfection of a thing does not annul its existence, but, on the contrary, asserts it. Imperfection, on the other hand, does annul it; therefore we cannot be more certain of the existence of anything, than of the existence of a being absolutely infinite or perfect--that is, of God. For inasmuch as his essence excludes all imperfection, and involves absolute perfection, all cause for doubt concerning his existence is done away, and the utmost certainty on the question is given. This, I think, will be evident to every moderately attentive reader.
Modern English
In this last proof I have shown God's existence a posteriori, so the demonstration could be more easily grasped — not because his existence does not also follow a priori from the same ground. For since being able to exist is a power, it follows that the more reality belongs to a thing's nature, the more force it has from itself to exist. An absolutely infinite being, God, therefore has from himself an absolutely infinite power of existing, and on that account exists absolutely.
Many will perhaps fail to see the force of this proof, because they are accustomed to consider only things that come about through external causes. They see that what comes into existence easily also passes away easily; and they judge things harder to bring about, things they conceive as having more parts, to be less easily brought to exist.
To free them from this prejudice, I need not show here why the saying 'what comes quickly, passes quickly' is true, nor whether all things are equally easy from the standpoint of nature as a whole. It is enough to note that I am not speaking here of things produced by external causes, but only of substances, which cannot be produced by any external cause (E1P6). Things produced by external causes, whether they have many parts or few, owe whatever perfection or reality they possess to the force of that external cause; their existence therefore arises from the perfection of the external cause, not from their own.
But whatever perfection a substance has, it owes to no external cause. Its existence must follow from its own nature alone, which is nothing other than its essence. The perfection of a thing does not undo its existence; on the contrary, it asserts it. Imperfection, by contrast, does undo it. So we can be more certain of no thing's existence than of the existence of an absolutely infinite, perfect being, that is, God. Since his essence excludes every imperfection and involves absolute perfection, it removes every reason to doubt his existence and gives the highest certainty of it. This will be clear, I believe, to anyone even moderately attentive.