Analogical reasoning

“ Reasoning by Analogy differs only in degree from that kind of reasoning called 'Generalization.' When many things resemble each other in a few properties, we argue about them by Generalization. When a few things resemble each other in many properties, it is a case of analogy. ”

“ Nothing is incomprehensible if we adopt the doctrine of analogy; which, as more than one great writer observes, is an irrefragable proof that man is endowed with reasoning powers. The gentleman, whose house you now see, sir, sleeps by day, and dines at midnight. ”

“ These are a few analogous laws which I have taken almost at random; but it must strike the most casual listener to my remarks that it is wondrous strange that men, regarded as social beings, should possess the same qualities, and be governed by the same laws, as the rest of matter. As Bishop Butler says, ‘the force of analogy consists in the frequency of the supposed analogous facts, and the real resemblance of the things compared.’ It appeals to the reasoning faculty, and may form a solid argument. ”

“ It must be reeollected that our conception of mind, even in our fellow men, is based entirely on analogy, and thus the further we depart from the human type, the lower we go in the organic scale, the weaker and weaker must that analogy become, and the more careful must we be to avoid the conception that any apparently purposive actions we may observe in these lower organisms must be due to trains of reasoning such as we find in ourselves. ”

“ This is what the philosophers call analogy. Analogy is thus founded on experience, and is, therefore, far less perfect than intuition or demonstration. That gravitation will always continue is analogical ”

“ The hypothesis that other people have minds must, I think, be allowed to be not susceptible of any very strong support from the analogical argument. At the same time, it is a hypothesis which systematises a vast body of facts and never leads to any consequences which there is reason to think false. ”

“ The traditional Logic of the text-books, when it reasons from universals to their subalternate particulars, or derives particular conclusions from universal premises, does so by tacitly and, in general, by unjustifiably assuming the external existence of the objects reasoned about, while all the time still sundering external and internal. Reasoning itself is, to be sure, experience, but is, by hypothesis, experience of internal meanings, not of the external meanings which are taken, by this sort of thinking, to be the Reality. ”

“ It is usual to point out that Psychology tries to explain the subjective processes of conception, judgment and reasoning, and to give their natural history; but that Logic is wholly concerned with the results of such processes, with concepts, judgments and reasonings, and merely with the validity of the results, that is, with their truth or consistency; whilst Psychology has nothing to do with their validity, but only with their causes. ”

“ The one theory may be found to fit the facts and the other may be condemned; but without some analogy as a guide how are such theories to be devised? What we require in science are continual stimuli to start us on new experiments, new observations, and new ideas, and prevent us, especially those who are teachers, from constantly repeating the old ones.
I shall be satisfied if the present lecture is regarded as a plea for the use of reasoning from analogy, and as an illustration of its value. ”

“ The nearest approach which human theories can make to perfection is to diminish this residue, this caput mortuum of observation, as it may be considered, as much as practicable, and, if possible, to reduce it to nothing, either by showing that something has been neglected in our estimation of known causes, or by reasoning upon it as a new fact, and on the principle of the inductive philosophy ascending from the effect to its cause or causes. ”

“ The natural history account of analogy will consider the status in less advanced stages of human development, and the evolution of this form of thought, which scientists to-day use only with the greatest caution, and to which they at best assign but a limited and corroborative value. It will appear that analogy is dominant in primitive types of thought ”

“ But, if so, it is difficult to arrive at any causal laws, and arguments from analogy are more misleading than we are inclined to think them. As a matter of fact, the whole structure of science, as well as the world of common sense, demands the use of induction and analogy if it is to be believed. These forms of inference, therefore, rather than deduction, are those that must be examined if we are to accept the world of science or any world outside of our own dreams. ”

“ If, he says in the fourth paragraph of the Note, ‘If we examine those arguments which, in any of the sciences above mentioned, are supposed to be the mere effects of reasoning and reflection, they will be found to terminate at last in some general principle or conclusion for which we can assign no reason but observation and experience.’ If an argument be not a process of reasoning, neither word is intelligible. ”

“ Every phenomenon or so-called 'fact' has an infinity of aspects or properties, as we have seen, amongst which the fool, or man with little sagacity, will inevitably go astray. But no matter for this point now. The first thing is to have seen that every possible case of reasoning involves the extraction of a particular partial aspect of the phenomena thought about, and that whilst Empirical Thought simply associates phenomena in their entirety, Reasoned Thought couples them by the conscious use of this extract. ”

“ Whether God and duty are realities, the existence of which is manifest to us a priori by the constitution of our rational faculty; or whether our ideas of them are acquired notions, the origin of which we are able to trace and explain; and the reality of the objects themselves a question not of consciousness or intuition, but of evidence and reasoning.
The province of logic must be restricted to that portion of our knowledge which consists of inferences from truths previously known; whether those antecedent data be general propositions, or particular observations and perceptions. ”

“ Reasoning from Analogy. Analogy in its most tenuous form is weak as a basis for an actual inference, though it is often effective as a means of expressing an intuitive judgment where the reasons are too subtle and diffused for formal explanation. When Lincoln in the middle of the Civil War said that men do not swap horses while they are crossing a stream, the analog, though subtle, was felt to be real. Popular adages and proverbs are common modes of expressing such deep-lying analogies: for example, "Where there is smoke there is fire"; "The slothful man saith, There is a lion in the way." ”

“ It is in this last respect that considerations of analogy have the highest scientific value. The cases in which analogical evidence affords in itself any very high degree of probability, are, as we have observed, only those in which the resemblance is very close and extensive; but there is no analogy, however faint, which may not be of the utmost value in suggesting experiments or observations that may lead to more positive conclusions. ”

“ Analogy is indeed the breadth of truth, because it shows how the true is true diversely in many things or parallel fields; and, in continuity with that analogy which consists in the relation between parallel streams of existence, there is that mere likeness which appears every now and then on the very surface of nature, and proclaims a connection where its reason and principle are at present inscrutable. ”

“ This mode of expression, exhibiting as the type of all reasoning from experience "The men A, B, C, etc., are so and so, therefore any man is so and so," would much better manifest the true idea--that inductive reasoning is always, at bottom, inference from particulars to particulars, and that the whole function of general propositions in reasoning, is to vouch for the legitimacy of such inferences. ”

“ Men, taken historically, reason by analogy long before they have learned to reason by abstract characters. Association by similarity and true reasoning may have identical results. If a philosopher wishes to prove to you why you should do a certain thing, he may do so by using abstract considerations exclusively; a savage will prove the same by reminding you of a similar case in which you notoriously do as he now proposes, and this with no ability to state the point in which the cases are similar. ”

“ True, by analogies one may conceive it, as the religious man thinks of God's personality, or as the philosopher thinks of the unity of his world, or as the scientist thinks of nature's law; but the analogies are always so many tethers, and are accordingly necessarily partial, whereas no whole can ever be quite in kind with any of its parts. We may conceive reality, then, by the use of analogy—that is, by projecting what we do know of one or another side of life beyond its natural sphere ”

“ We have words which are proper, and not analogical, to express the various ways in which we perceive external objects by the senses; such as feeling, sight, taste: but we are often obliged to use these words analogically, to express other powers of the mind which are of a very different nature. And the powers which imply some degree of reflection, have generally no names but such as are analogical. The objects of thought are said to be in the mind, to be apprehended, comprehended, conceived, imagined, retained, weighed, ruminated. ”

“ No analogy can prove creation, because no analogy can prove what it does not contain, namely, an example of creation." [276] "Analogy, the specious precursor of reason, would suggest the personality of the powers which awed and cheered man. Reason sends us to facts as the only positive grounds of positive conclusions; but in the childhood of intellect and experience, likelihood is mistaken for certainty, and probability for fact. ”

“ True analogy is of use as throwing light on Laws of Thought; it teaches, not Truth in itself but the nature of the relation of the human consciousness to Truth. True Logic is not dogmatic about facts; it clears the ground of false conclusions, and leaves The Eternal Pulsation to speak in silence to the soul. ”

“ It became the function of reason to develop, out of the material furnished by the senses, a knowledge of the true nature of the system external to man and involving him in its scope which we call universe. In the carrying out of this function the analogical process has remained, but the analogies utilized, from being likenesses between what things seem to be to the senses, have more and more become analogies between propositions made regarding what things do, regarding how things act upon, are related to and determine each other. ”

“ All our reasonings concerning matter of fact are founded on a species of Analogy, which leads us to expect from any cause the same events, which we have observed to result from similar causes. Where the causes are entirely similar, the analogy is perfect, and the inference, drawn from it, is regarded as certain and conclusive: nor does any man ever entertain a doubt, where he sees a piece of iron, that it will have weight and cohesion of parts; as in all other instances, which have ever fallen under his observation. ”

“ But Reasoning, even in the widest sense of which the word is susceptible, does not seem to comprehend all that is included, either in the best, or even in the most current, conception of the scope and province of our science. The employment of the word Logic to denote the theory of argumentation, is derived from the Aristotelian, or, as they are commonly termed, the scholastic logicians. ”

“ There is hardly any doubt of the well-known fact that science has much to thank analogy for, since analogy is the simplest and easiest means for progress in thought. If anything is established in any one direction but progress is desired in another, then the attempt is made to adapt what is known to the proximate unknown and to draw the possible inference by analogy. ”

“ The irresistible laws of thought constrain us to believe that the precise limits of our actual ideas are not the actual limits of possible ideas; the law, according to which these deductions are drawn, is called analogy; and this is the foundation of all our inferences, from one idea to another, inasmuch as they resemble each other.
We see trees, houses, fields, living beings in our own shape, and in shapes more or less analogous to our own. These are perpetually changing the mode of their existence relatively to us. ”

“ But however lacking in definiteness or formulation, however unconsciously realized and barely expressible, the tendency or disposition to believe is communicated to others and becomes an influential factor in the ultimate fixation of belief and in the guidance of conduct. Logically considered, analogy is always a weak argument; and becomes weaker, as the range of observed resemblance is more and more limited, as the resemblances belong to accidental, unessential traits, and as the underlying basis of the inference is removed from direct verification. ”

“ It follows that every hypothesis worthy of consideration must suggest some likeness, analogy, or common law, acting in two or more things. If, in order to explain certain facts, a, a′, a′′, &c., we invent a cause A, then we must in some degree appeal to experience as to the mode in which A will act. As the laws of nature are not known to the mind intuitively, we must point out some other cause, B, which supplies the requisite notions, and all we do is to invent a fourth term to an analogy. ”