On this question the opinions of competent and unprejudiced judges disagree. By an eminent and accomplished writer the case is summed up as follows, in the Harveian Oration for 1865. Having previously included the material factor under mechanical adaptation as distinguished from art in the highest sense, Dr. Acland goes on to say (page 13): "The illustration of the watch so quaintly employed by Nieuwentyt, and so entirely appropriated by Paley, only in a coarse way suggests the parallel between infinite art and common mechanical skill. It has done some mischief to the cause it advocates, by making familiar a rude illustration, which minds without imagination, or void of constructive power, have accepted as a recognised explanation of the method of operation by an Infinite Creative Will."
Paley's critics should however observe, that he did not himself intend the objectionable inference. Probably he never even perceived that it might be drawn from his comparison. Abstract inquiries connected with Theism, he banished to the end of his book, where they are discussed in a manner little calculated to satisfy any readers who have ever felt them as substantial difficulties.[18] But then, he would most likely have referred these persons to the writings of professed metaphysicians. It may be wise for us to take warning both by what Paley did and by what he left undone. Some deeper questions are indispensable to the argument from Design, but we shall follow his example so far as to avoid such disquisitions as were current in his day under the name of metaphysics. On the other hand we shall draw the required data from that critical Fact-philosophy of Mind and Human Nature, which forms to so many thinkers the birth-star of a new science, one amongst the rising hopes of our nineteenth century.
Meantime, our business on hand is to rebut the present accusation of proving too much, brought against Paley's analogy. We shall try to complete our answer by setting his argument in the point of view under which he evidently meant it to be looked at.
Either as an illustration or as a means of proof, Analogy need not hold in more than a single point; provided only that this single point is clear and well-established—resting, for example, on a moral law or a causal nexus. Any one who desires to make an analytical investigation into this law of inference will receive valuable aid from Ueberweg's Logic, §§ 131 and 2, particularly if compared with § 129.
To a common-sense mind we may give sufficient satisfaction by adducing one or two good analogies. Thus, for instance, the duties of a religious minister are often explained by saying that he ought to be the shepherd of his flock; that is, his relation to his people ought to resemble that of the shepherd to his sheep. We all understand how truly is here expressed a world of watchful care. But are all points of the relation to be implied? May the spiritual pastor ever become the slayer or the salesman of his flock?
Again,—writers upon political subjects some years ago used very commonly to quote from the days of Alfred the Great supposed precedents for our most modern constitutional dicta. In many cases the thing defended was a legitimate outgrowth of the precedent cited; but to pronounce the two identical seemed sufficiently absurd. In confutation of some such absurdities, clever men argued that the body corporate has, like the individual body, its childhood, growth, and maturity. The argument became generally accepted, and got extended to the distinctions between healthy increase and sickly degeneration, with other like inferences. The further conclusion was next drawn, that every national body resembles the human frame in a necessary decay, and inevitable mortality. Now, whatever opinion may be entertained as to the fact of a death-rate of nationalities, nothing seems more certain than that those who first employed the comparison never contemplated this particular corollary. Whether their first use of it was wise or unwise, has been, like Paley's Watch-analogy, a matter of some considerable dispute.
The general subject of Analogy, rightly or wrongly extended, admits of wider illustration.
Simile and metaphor are often compressed analogies, and many of them gain in beauty from expansion. Pope's celebrated comparison of the traveller ascending the Alps with the student who scales the heights of literature; and how
"Hills peep o'er hills, and Alps on Alps arise;"
is a good example of a poet's successfully expanding his own thought. Still more exquisitively true to nature is the final parallel drawn in Coleridge's description of the divided friends who stood apart,—