{270} Conviction, as to theism, is not forced upon men as is the conviction of the existence of the sun at noon-day.[286] A moral element enters also here, and the analogy there is in this respect between Christianity and theism speaks eloquently of their primary derivation from one common author.
Thus we might expect that it would be a vain task to seek anywhere in nature for evidence of Divine action, such that no one could sanely deny it.

God will not allow Himself to be caught at the bottom of any man's crucible, or yield Himself to the experiments of gross-minded and irreverent inquirers.

The natural, like the supernatural, revelation appeals to _the whole_ of man's mental nature and not to the _reason alone_.[287] None, therefore, need feel disappointed that evidence of the direct action of the first cause in merely natural phenomena ever eludes our grasp; for assuredly those same phenomena will ever remain fundamentally inexplicable by physical science alone.
There being then nothing in either authority or reason which makes "evolution" repugnant to Christianity, is there anything in the Christian doctrine of "Creation" which is repugnant to the theory of "evolution"?
Enough has been said as to the distinction between absolute and derivative "creation." It remains to consider the successive "evolution" (Darwinian and other) of "specific forms," in a theological light.
As to what "evolution" is, we cannot of course hope to explain it completely, but it may be enough to define it as the manifestation to the intellect, by means of sensible impressions, of some ideal entity (power, principle, nature, or activity) which before that manifestation was in{271} a latent, unrealized, and merely "potential" state--a state that is capable of becoming realized, actual, or manifest, the requisite conditions being supplied.
"Specific forms," kinds or species, are (as was said in the introductory chapter) "peculiar congeries of characters or attributes, innate powers and qualities, and a certain nature realized in individuals." Thus, then, the "evolution of specific forms" means the actual manifestation of special powers, or natures, which before were latent, in such a successive manner that there is in some way a genetic relation between posterior manifestations and those which preceded them.
On the special Darwinian hypothesis the manifestation of these forms is determined simply by the survival of the fittest of many indefinite variations.
On the hypothesis here advocated the manifestation is controlled and helped by such survival, but depends on some unknown internal law or laws which determine variation at special times and in special directions.
Professor Agassiz objects to the evolution theory, on the ground that "species, genera, families, &c., exist as thoughts, individuals as facts,"[288] and he offers the dilemma, "If species do not exist at all, as the supporters of the transmutation theory maintain, how can they vary?
and if individuals alone exist, how can the differences which may be observed among them prove the variability of species ?" But the supporter of "evolution" need only maintain that the several "kinds" become manifested gradually by slight differences among the various individual embodiments of one specific idea.

He might reply to the dilemma by saying, species do not exist _as species_ in the sense in which they are said to vary (variation applying only to the concrete embodiments of {272} the specific idea), and the evolution of species is demonstrated not by individuals _as individuals_, but as embodiments of different specific ideas.
Some persons seem to object to the term "creation" being applied to evolution, because evolution is an "exceedingly slow and gradual process." Now even if it were demonstrated that such is really the case, it may be asked, what is "slow and gradual"?
The terms are simply relative, and the evolution of a specific form in ten thousand years would be instantaneous to a being whose days were as hundreds of millions of years.
There are others again who are inclined absolutely to deny the existence of species altogether, on the ground that their evolution is so gradual that if we could see all the stages it would be impossible to say _when_ the manifestation of the old specific form ceased and that of the new one began.

But surely it is no approach to a reason against the existence of a thing that we cannot determine the exact moment of its first manifestation.
When watching "dissolving views," who can tell, whilst closely observing the gradual changes, exactly at what moment a new picture, say St.Mark's, Venice, can be said to have commenced its manifestation, or have begun to dominate a preceding representation of "Dotheboys' Hall"?
That, however, is no reason for denying the complete difference between the two pictures and the ideas they respectively embody.
The notion of a special nature, a peculiar innate power and activity--what the scholastics called a "substantial form"-- will be distasteful to many.
The objection to the notion seems, however, to be a futile one, for it is absolutely impossible to altogether avoid such a conception and such an assumption.