It thus comes very much to Pope's solution:

Why has not man a microscopic eye?
For this plain reason: man is not a fly,—

and in view of his subsequent admissions, Helmholtz's flourish about returning the eye to its maker looks very like theatrical clap-trap, unworthy of such a man.

[131] Life of C. Darwin, ii. 234. Erasmus Darwin to C. Darwin, November 23, 1859.

[132] Animal Locomotion (International Scientific Series), p. 180.

[133] Origin of Laws of Nature, p. 69.

[134] Lectures on Evolution (Cheap Edition), p. 37.

[135] Philosophical Basis of Evolution, passim.

[136] By a Final Cause is meant the predetermined result or end, towards which a work of intelligence is directed, the end being the ultimate cause of the whole act. Thus the obtaining a light is the Final Cause of striking a match: while the striking of the match is the Efficient Cause producing the light.

[137] Grammar of Assent, p. 69.