Guessing

“ Those philosophers, who have divided human reason into knowledge and probability, and have defin’d the first to be that evidence, which arises from the comparison of ideas, are oblig’d to comprehend all our arguments from causes or effects under the general term of probability. ”

“ Perception being infallible evidence of whatever is really perceived, the error now under consideration can be committed no otherwise than by mistaking for conception what is, in fact, inference. We have formerly shown how intimately the two are blended in almost every thing which is called observation, and still more in every Description.255 What is actually on any occasion perceived by our senses being so minute in amount, and generally so unimportant a portion of the state of facts which we wish to ascertain or to communicate ”

“ Do you need to be cudgelled with a whole universe to begin to learn to guess? What is all your science—your boasted science, after all, but more raw material to make more guesses with? Is not the whole Future Tense an inference? Is not History—that which has actually happened—a mystery? You yourself are a mere probability, and God is a generalisation. What does it profit a man to discover The Inductive Method and to lose his own soul? ”

“ Of the science, therefore, which expounds the operations of the human understanding in the pursuit of truth, one essential part is the inquiry: What are the facts which are the objects of intuition or consciousness, and what are those which we merely infer? But this inquiry has never been considered a portion of logic. ”

“ And herein lies the difference between probability and certainty, faith, and knowledge, that in all the parts of knowledge there is intuition ; each immediate idea, each step has its visible and certain connexion : in belief, not so. That which makes me believe, is something extraneous to the thing I believe ; something not evidently joined on both sides to, and so not manifestly showing the agreement or disagreement of those ideas that are under consideration.
4. The grounds of probability are two : conformity with our own experience, or the testimony of others’ experience. ”

“ Why should we want to know the probability that the fact will accord with our conclusion? That implies that we are interested in all possible worlds, and not merely the one in which we find ourselves placed. ”

“ Whilst Psychology explains how the mind goes forward from data to conclusions, Logic takes a conclusion and goes back to the data, inquiring whether those data, together with any other evidence (facts or principles) that can be collected, are of a nature to warrant the conclusion. ”

“ The perception of distance by the eye, which seems so like intuition, is thus, in reality, an inference grounded on experience; an inference, too, which we learn to make; and which we make with more and more correctness as our experience increases ”

“ If there be necessary and universal truths expressible in propositions of axiomatic simplicity and obviousness, and having for their subject-matter the elements of all our experience and all our knowledge, surely these are the truths which, if experience suggest to us any truths at all, it ought to suggest most readily, clearly, and unceasingly. ”

“ Our assent to the conclusion being grounded on the truth of the premisses, we never could arrive at any knowledge by reasoning, unless something could be known antecedently to all reasoning.
Examples of truths known to us by immediate consciousness, are our own bodily sensations and mental feelings. I know directly, and of my own knowledge, that I was vexed yesterday, or that I am hungry to-day. Examples of truths which we know only by way of inference, are occurrences which took place while we were absent, the events recorded in history, or the theorems of mathematics. ”

“ We ask ourselves the general question: 'WHAT DO WE EXPERIENCE WHEN WE THINK?' Then we do not at all attempt a preliminary determination of the concept 'thought,' but choose for analysis only such processes as everyone would describe as processes of thought. ”

“ I shall venture to affirm as a general proposition which admits of no exception, that the knowledge of this relation is not, in any instance, attained by reasonings a priori; but arises entirely from experience, when we find that any particular objects are constantly conjoined with each other; ... nor can our reason, unassisted by experience, ever draw any inference concerning real existence and matter of fact. ”

“ If we assume one hypothesis to be true, a hundred others rush in upon the mind, and demand consideration. From every one of these a host of interesting conclusions can be drawn, each suggesting another, until the brain grows weary of action. ”

“ This general situation of our thought in all those branches of inquiry where, as very often in mathematics, we deal with universal truth, and reason out results about Being, while still viewing Reality as Another than thought, is a situation that stimulates us to manifold inquiries. ”

“ Observation extends only to the sensations by which we recognize objects; but the propositions which we make use of, either in science or in common life, relate mostly to the objects themselves. In every act of what is called observation, there is at least one inference—from the sensations to the presence of the object ”

“ This proposition I take to be a mere interpretation of universal experience, a statement in words of what every one is internally convinced of. No one who believed that he knew thoroughly the circumstances of any case, and the characters of the different persons concerned, would hesitate to foretell how all of them would act. Whatever degree of doubt he may in fact feel, arises from the uncertainty whether he really knows the circumstances, or the character of some one or other of the persons, with the degree of accuracy required ”

“ At least that is what it would be like if your guesses were accurate, not only in their statement, but also in their proportion, and also in their order. It is millions to one that your guesses are nothing of the kind. ”

“ Finding the minor premise is a matter of observation, and if you fail to observe the significant fact about the problem, the really useful major premise may lie dormant, known and retained but not recalled, while false clues suggest inapplicable major premises and give birth to plenty of reasoning but all to no purpose. Some persons with abundant knowledge are ineffective reasoners from lack of a sense for probability. The efficient reasoner must be a good guesser. ”

“ 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. ”

“ These remarkable speculations—the workings of a mind in which a powerful imagination allied itself with superior reasoning faculties, the marvellous current of whose thought ran only in the diked and guarded channels of mathematical demonstration—he uniformly speaks of as "facts." ”

“ In such noble and sublime studies as these, 'tis a glory to arrive at probability, and the search itself rewards the pains. But there are many degrees of probable, some nearer to the truth than others, in the determining of which lies the chief exercise of our judgment. ”

“ Experience and testimonies clashing infinitely vary the degrees of probability. Thus far the matter goes easy enough. Probability upon such grounds carries so much evidence with it, that it naturally determines the judgment, and leaves us as little liberty to believe or disbelieve, as a demonstration does, whether we will know, or be ignorant. ”

“ A person observing the occurrence of certain facts and phenomena asks, naturally enough, what process, what kind of operation known to occur in Nature applied to the particular case, will unravel and explain the mystery? Hence you have the scientific hypothesis; and its value will be proportionate to the care and completeness with which its basis had been tested and verified. It is in these matters as in the commonest affairs of practical life: the guess of the fool will be folly, while the guess of the wise man will contain wisdom. ”

“ We should never predicate probabilities except on some degree of actual evidence, or some likelihood of occurrence, falling within the limits, analogically or otherwise, of human observation and experience. ”

“ What warrant have we, beyond undemonstrable probability, that the attributes of that portion of matter that can be reached by the senses belong also to all that portion of which the senses can directly teach us nothing? ”

“ The beginning of all knowledge is observation. It has been shown by Mr. Mill that 'axioms,' which lie at the foundation of all reasoning and all science, 'are experimental truths—generalisations from observation. ”

“ Psychologists point out how much of what we think we see is supplied by association or unconscious inference, how much is mental interpretation, and how doubtful is the residuum which can be regarded as crude datum. ”

“ In the case of a strongly intuitive mind, it might be possible to guess the exact order of three or four apparently disconnected events, but to arbitrarily associate with them other and more distinctively subordinate occurrences, like the appearance or disappearance of whole groups and classes of plants and animals, the supposition that guess-work, and not positive information, governed in the formation of a judgment, is at once rejected because of its utter incredibility. ”

“ Having obtained by observation or experience a certain number of simple facts, and thence deduced the general qualities of bodies, we are enabled, by demonstrative reasoning, to discover other facts which have never fallen under our observation, or, if so, may have never excited attention. ”

“ On the other hand, if we add observation to observation without attempting to draw not only certain conclusions but also conjectural views from them, we offend against the very end for which only observations ought to be made. ”

“ In almost every case where we are called upon to form a judgment, and to act upon it, the premises are so uncertain, the conditions of the problem so numerous and so little known, and its relations to other things admit of so much variation, that our conclusion can be nothing but a probability ”

“ When therefore we see other creatures, in millions of instances, perform like actions, and direct them to like ends, all our principles of reason and probability carry us with an invincible force to believe the existence of a like cause. ”

“ The same is true of the theories of every other man, for a theory is only a guess, and you cannot guess or imagine the truth. No one has ever satisfactorily answered the question, "Why?" as most scientific men are well aware, and I did not feel that I could do better than others who had tried and failed. ”

“ Does not an account of thinking, basing itself on modern scientific procedure, demand a statement in which all the distinctions and terms of thought—judgment, concept, inference, subject, predicate, and copula of judgment, etc., ad infinitum—shall be interpreted simply and entirely as distinctive functions or divisions of labor within the doubt-inquiry process? ”

“ As demonstration is subject to the controul of probability, so is probability liable to a new correction by a reflex act of the mind, wherein the nature of our understanding, and our reasoning from the first probability become our objects. ”

“ If the senses cannot be used, because the event is in the future, or out of reach, how can reasoning take their place? Apparently, at least, we must infer the unknown from the known, and the mind must itself create an addition to the sum of knowledge. ”

“ These probabilities rise so near to certainty, that they govern our thoughts as absolutely, and influence all our actions as fully, as the most evident demonstration ; and in what concerns us we make little or no difference between them and certain knowledge. ”

“ In some problems, for example, the analysis of space and time, the nature of perception, or the theory of judgment, the discovery of the logical form of the facts involved is the hardest part of the work and the part whose performance has been most lacking hitherto. ”

“ The fact that the processes of perception, memory, and anticipation are transformed in their82 logical operation into sensations and universals, terms, and relations, and, as such, become the subject-matter of logical theory, does not mean that they have lost their mediating character, and have become merely objects of logical contemplation at large. Sensations or sense-data, and ideas, terms and relations, are the subject-matter of logical theory for the reason that they sometimes succeed and sometimes fail in their logical operations. ”

“ Reasoning is that operation of the sensorium by which we excite two or many tribes of ideas, and then reexcite the ideas in which they differ or correspond. If we determine this difference, it is called judgment; if we in vain endeavour to determine it, it is called doubting. ”

“ Supposing evidence to be ultimately nothing but accumulated experience, the amount of it in favour of causation is incomparably greater than the most that has ever been advanced to show the probability of any other kind of event; and every relation of events which is shown to have the marks of causation obtains the support of that incomparably greater body of evidence. ”

“ Let men be once fully perswaded of these two principles, That there is nothing in any object, consider'd in itself, which can afford us a reason for drawing a conclusion beyond it; and, That even after the observation of the frequent or constant conjunction of objects, we have no reason to draw any inference concerning any object beyond those of which we have had experience; ”