All the examples adduced have been drawn, without exception, from judgements, and not from things.But the unconditioned necessity of a judgement does not form the absolute necessity of a thing.On the contrary, the absolute necessity of a judgement is only a conditioned necessity of a thing, or of the predicate in a judgement.The proposition above-mentioned does not enounce that three angles necessarily exist, but, upon condition that a ******** exists, three angles must necessarily exist- in it.And thus this logical necessity has been the source of the greatest delusions.
Having formed an a priori conception of a thing, the content of which was made to embrace existence, we believed ourselves safe in concluding that, because existence belongs necessarily to the object of the conception (that is, under the condition of my positing this thing as given), the existence of the thing is also posited necessarily, and that it is therefore absolutely necessary- merely because its existence has been cogitated in the conception.
If, in an identical judgement, I annihilate the predicate in thought, and retain the subject, a contradiction is the result; and hence I say, the former belongs necessarily to the latter.But if Isuppress both subject and predicate in thought, no contradiction arises; for there is nothing at all, and therefore no means of forming a contradiction.To suppose the existence of a ******** and not that of its three angles, is self-contradictory; but to suppose the non-existence of both ******** and angles is perfectly admissible.And so is it with the conception of an absolutely necessary being.
Annihilate its existence in thought, and you annihilate the thing itself with all its predicates; how then can there be any room for contradiction? Externally, there is nothing to give rise to a contradiction, for a thing cannot be necessary externally; nor internally, for, by the annihilation or suppression of the thing itself, its internal properties are also annihilated.God is omnipotent- that is a necessary judgement.His omnipotence cannot be denied, if the existence of a Deity is posited- the existence, that is, of an infinite being, the two conceptions being identical.But when you say, God does not exist, neither omnipotence nor any other predicate is affirmed; they must all disappear with the subject, and in this judgement there cannot exist the least self-contradiction.
You have thus seen that when the predicate of a judgement is annihilated in thought along with the subject, no internal contradiction can arise, be the predicate what it may.There is no possibility of evading the conclusion- you find yourselves compelled to declare: There are certain subjects which cannot be annihilated in thought.But this is nothing more than saying: There exist subjects which are absolutely necessary- the very hypothesis which you are called upon to establish.For I find myself unable to form the slightest conception of a thing which when annihilated in thought with all its predicates, leaves behind a contradiction; and contradiction is the only criterion of impossibility in the sphere of pure a priori conceptions.
Against these general considerations, the justice of which no one can dispute, one argument is adduced, which is regarded as furnishing a satisfactory demonstration from the fact.It is affirmed that there is one and only one conception, in which the non-being or annihilation of the object is self-contradictory, and this is the conception of an ens realissimum.It possesses, you say, all reality, and you feel yourselves justified in admitting the possibility of such a being.(This I am willing to grant for the present, although the existence of a conception which is not self-contradictory is far from being sufficient to prove the possibility of an object.)* Now the notion of all reality embraces in it that of existence; the notion of existence lies, therefore, in the conception of this possible thing.If this thing is annihilated in thought, the internal possibility of the thing is also annihilated, which is self-contradictory.
*A conception is always possible, if it is not self-contradictory.
This is the logical criterion of possibility, distinguishing the object of such a conception from the nihil negativum.But it may be, notwithstanding, an empty conception, unless the objective reality of this synthesis, but which it is generated, is demonstrated; and a proof of this kind must be based upon principles of possible experience, and not upon the principle of analysis or contradiction.
This remark may be serviceable as a warning against concluding, from the possibility of a conception- which is logical- the possibility of a thing- which is real.