Let us carry the thing further, and take for granted the most wonderful instances that are given of the skill and forecast of animals.  Let us admire, as much as you please, the certainty with which a hound takes a spring into a third way, as soon as he finds by his nose that the game he pursues has left no scent in the other two.  Let us admire the hind, who, they say, throws a good way off her young fawn, into some hidden place, that the hounds may not find him out by the scent of his strain.  Let us even admire the spider who with her cobwebs lays subtle snares to trap flies, and fall unawares upon them before they can disentangle themselves.  Let us also admire the hern, who, they say, puts his head under his wing, in order to hide his bill under his feathers, thereby to stick the breast of the bird of prey that stoops at him.  Let us allow the truth of all these wonderful instances of rationality; for all nature is full of such prodigies.  But what must we infer from them?  In good earnest, if we carefully examine the matter, we shall find that they prove too much.  Shall we say that animals are more rational than we?  Their instinct has undoubtedly more certainty than our conjectures.  They have learnt neither logic nor geometry, neither have they any course or method of improvement, or any science.  Whatever they do is done of a sudden without study, preparation, or deliberation.  We commit blunders and mistakes every hour of the day after we have a long while argued and consulted together; whereas animals, without any reasoning or premeditation, perform every hour what seems to require most discernment, choice, and exactness.  Their instinct is in many things infallible; but that word instinct is but a fair name void of sense.  For what can an instinct more just, exact, precise, and certain than reason itself mean but a more perfect reason?  We must therefore suppose a wonderful reason and understanding either in the work or in the artificer; either in the machine or in him that made it.  When, for instance, I find that a watch shows the hours with such exactness as surpasses my knowledge, I presently conclude that if the watch itself does not reason, it must have been made by an artificer who, in that particular, reasoned better and had more skill than myself.  In like manner, when I see animals, who every moment perform actions that argue a more certain art and industry than I am master of, I immediately conclude that such marvellous art must necessarily be either in the machine or in the artificer that framed it.  Is it in the animal himself?  But how is it possible he should be so wise and so infallible in some things?  And if this art is not in him, it must of necessity be in the Supreme Artificer that made that piece of work, just as all the art of a watch is in the skill of the watchmaker.