This is a considerable stretch of analogy ; but it is greatly exceeded by that spirit of generalization, which ascribes life and sensibility to stones. " The vegeta tion of stones," says the Bishop of Llandaff, " bath been admitted by many ; and some have contended, that mine rals, as well as animals and vegetables, siring from seed ; the greatest being nothing but the expansion of the parts of a minute grain of sand." " I do not know," adds he, " whether it would be a very extravagant conjecture, which should suppose, that all matter is, or has been, organised, enlivened, and animated." Watson's C'hemi cal Essays, vol. v.
\Ve infer from analogy, with a high degree of proba bility, that the planets are peopled with inhabitants, on account of their numerous points of resemblance with our earth. They all revolve round the sun as the earth does, and are governed in their revolution by the same law of gravitation. They all, like the earth, borrow their light from the sun, and most of them are known to have a rotation on their axes ; and therefore, like the earth, to have a vicissitude of day and night. Several of them likewise are attended by moons as the earth is. From these manifold points of resemblance, it is highly rea sonable to conclude, that these bodies are, like our earth, destined to be the habitation of various orders of living creatures. Such an argument, drawn from analogy, is perfectly legitimate, and carries with it the greatest probability. But who can help smiling at the extent to which the learned \Volfius carries this kind of analogi cal reasoning, when he proceeds upon it to calculate the precise dimensions of the supposed inhabitants of the diflerent planets ! (See E'en/. ./Ntron. Gcncv. 1733, part •d.) The inhabitants of Jupiter, he thinks, must be giants ; and he grounds his opinion chiefly on the small degree of solar light which they enjoy ; so that the pu pils of their eyes, and consequently their whole bodies, must be considerably larger than ours. Ile fixes the medium height of an inhabitant of Jupiter at Pa ris feet ; and this he finds to agree almost exactly with that of the famous Og, king of Basilan, whose bed, ac cording to Moses, was nine cubits and a quarter in length. This datum enables him, by means of a calcu lation concerning the Hebrew cubit, to fix the height of king Og, at 131iNg of the same feet.
In no branch science has reasoning from analogy been carried to a greater excess, than in the various departments of the philosophy of mind ; and no where has it been productive of greater errors. The early at tention of mankind is so completely engrossed by ma terial objects and their properties, that all their specu lations concerning intellect, receive a certain colouring and bias front this cause. The very names by which we dis tinguish the faculties of the mind, arc almost all borrow ed from the qualities of matter, of which we have examples in the words understanding, comp•ehending,imagining, cleliberating, and the like ; and the very soul, or sentient principle itself, is often distinguished by no other appel lation than that which is applied to the air or breath ; it is considered only as a .spiritus, 7rvevp.:4, or As there are no two kinds of existence of more oppo site qualities than body and mind, conclusions drawn front any supposed analogy between their properties, are peculiarly calculated to engender error. Yet such conclusions have been drawn with all the formality of reasoning, and considered as resting on a solid basis, notwithstanding the very absurd consequences in which they terminated. Of this the following remarkable ex ample is given by Dr Reid, " When a man is urged by contrary motives, those on one hand inviting him to do some action, those on the other to forbear it, he delibe rates about it, and at last resolves to do it, or not to do it. The contrary motives are here compared to the weights in the opposite scales of a balance ; and there is not, perhaps, any instance that can be named of a more striking analogy between body and mind. Hence the
phrases of weighing motives, of deliberating upon ac tions, are common to all languages. From this some philosophers draw very important conclusions. They say, that as the balance cannot incline to one side more than the other when the opposite weights are equal, so a man cannot possibly determine himself if the mo tives on both hands are equal; and as the balance must necessarily turn to that side which has most weight, so the man must necessarily be determined to that hand where the motive is strongest. On this foundation some of the schoolmen maintained, that if a hungry ass were placed between two bundles of hay, equally inviting, the beast must stand still, and starve to death, being unable to turn to either, because there are equal mo tives to both. This is an instance of that analogical rea soning which ought never to be trusted ; for the analogy between a balance and a man deliberating, though one of the strongest that can be found between matter and mind, is too weak to support any argument. A piece of dead, inactive matter, and an active intelligent are things very unlike ; and because the one would re main at rest in a certain case, it does not follow that the other would be inactive in a case somewhat similar. The argument is no better than this, that because a dead animal moves only as it is pushed, and if pushed with equal force in contrary directions, must remain at rest : therefore, the same thing must happen to a living ani mal ; for surely the similitude between a dead animal and a living one, is as great as that between a balance and a man." The conclusion drawn by Dr Reid, from his obser vations concerning analogy, is, that in our inquiries con cerning the mind and its operations, we ought never to trust to reasonings drawn Iron sonic, supposed simili tude of body to mind, and that we ought to u. very much upon our guard, that we be not imposed upon by those analogical terms and phrases, by which the operations of the mind are expressed in all languages. L6.9cty.s on th, Intellectual Powers., less. 1. c. iv.
No author has made a better or more appropriate use of the analogical mode of reasonim,. than Bisiop Butler. in his celebrated treatise entitled The Analogy of Re ligion, natural and revealed, to the constitution and course of nature." It is not the immediate design of this work to prove the truth of religion either natural or revealed, but to add to that proof, supposed to he already known• and to answer objections against it, by considerations drawn from analogy. When objections are made against the truths of religion, which may with equal force be urged against what we know to be true in the course of nature, such objections may justly be set aside as of no real weight. But it is shewn by the author of the Analogy, that the dispensations of Providence in the temporal affairs of this world, are entirely similar to that further dispensation to which we look forward in our hopes of a future and higher state of existence, that both may be traced up to the same general laws, and appear to be carried on according to the same plan of administra tion : there is, therefore, the highest presumption that both proceed from the same author, and are equally consistent with the immutable decrees of his perfect wisdom. In this manner has the author of the Analogy established a truth, which it is of the highest importance to learn, that the natural and moral worlds are inti mately connected, and parts of one stupendous system; and that the chief objections which are brought against religion may be urged with equal force against the con stitution and course of nature, where we know them to be false in fact. Thus has he, as it is well expressed by Mr Mainwaring (in the Dissertation prefixed to his volume of Sermons, p. 12.) " formed and concluded a happy alliance between faith and philosophy." (in)