On the whole, then, the eye appears to be an optical instrument of great ingenuity; and the conclusion that it must have been made by someone, and that whoever made it must have known and designed its use, seems inevitable.
These conclusions, it will be noticed, like the similar ones in regard to the watch, are not affected by our ignorance on many points. We may have no idea as to how an eye can be made, and yet feel certain that, as it exists, it must have been made by someone, and that its maker designed it for the purpose it serves.
Nor should we feel that the eye is explained by being told that every part of it has been produced in strict accordance with natural laws, and could not have been otherwise; in fact, that there is no design to account for. No doubt every single part has been thus produced, and if it stood alone there might be little to account for. But it does not stand alone. All the various and complicated parts of the eye agree in this one remarkable point, and in this one only, that they all help to enable man to see; and it is this that requires explanation. We feel that there must be some connection between the cause which brought all these parts together and the fact of man's seeing. In other words, the result must have been designed.
Nor does the fact that every organism in nature is produced from a previous one of the same kind alter this conclusion. Indeed, as was shown with reference to the watch, it can only increase our admiration for the skill which must have been spent on the first organism of each kind. Moreover, no part of the design can be attributed to the _parents_. If, for instance, the eyes of a child show design, it is not due to the intelligence or designing power of its father and mother. _They_ have not calculated the proper shape for the lens, or the mechanism of the iris, and as a rule know nothing whatever about it. And the same applies to _their_ parents, so that our going back ever so far in this way brings us no nearer to what we are in search of. The design is still unaccounted for, we still want a designer.
We hence conclude that the marks of design in the eye afford, at all events, what seems to be a very strong argument in favour of a _Designer_. And if only one eye existed in the universe, and there were no other mark of design in nature, this conclusion would be none the less clear.