Logicians From England

"[Boole's apparent goal was to] unfold the secret laws and relations of those high faculties of thought by which all beyond the merely perceptive knowledge of the world and of ourselves is attained or matured, is a object which does not stand in need of commendation to a rational mind."

"We endeavour to employ only symmetrical figures, such as should not only be an aid to reasoning, through the sense of sight, but should also be to some extent elegant in themselves."

"You will feel interested to know the fate of my mathematical speculations in Cambridge. One of the papers is already printed in the Mathematical Journal. Another, which I sent a short time ago, has been very favourably received, and will shortly be printed together with one I had previously sent."

"Some months ago I took the liberty of troubling you for a reference to Laplace. In your reply for which it still remains to me to thank you, you were pleased to express an interest in the subject of investigation alluded to in my letter. I have now drawn up a paper embodying the principal results of the inquiry which I have had some thoughts of laying before the Royal Society. Before taking a step of this nature I am however anxious to have the opinion of a more competent judge as to its propriety. Knowing that you have written much on kindred subjects, shall I presume too far on your courtesy in applying to you a second time?"

"Mr. Gregory: Late Fellow of Trinity College, Cambridge, and author of the -well-known Examples. Few in so short a life have done so much for science. The high sense which I entertain of his merits as a mathematician, is mingled with feelings of gratitude for much valuable assistance rendered to me in my earlier essays."

"I have spoken of the advantages of leisure and opportunity for improvement, as of a right to which you were entitled. I must now remind you that every right involves a responsibility. The greater our freedom from external restrictions, the more do we become the rightful subjects of the moral law within us. The less our accountability to man, the greater our accountability to a higher power. Such a thing as irresponsible right has no existence in this world. Even in the formation of opinion, which is of all things the freest from human control, and for which something like irresponsible right has been claimed, we are deeply answerable for the use we make of our reason, our means of information, and our various opportunities of arriving at a correct judgment. It is true, that so long as we observe the established rules of society, we are not to be called upon before any human court to answer for the application of our leisure; but so much the more are we bound by a higher than human law to redeem to the full our opportunities. Tho application of this general truth to the circumstances of your present position is obvious. A limited portion of leisure in the evening of each day is allotted to you, and it is incumbent upon you to consider how you may best employ it.'"

"(Martin Gardner) writes about various kinds of cranks with the conscious superiority of the scientist, and in most cases one can share his sense of the victory of reason. But after half a dozen chapters this non-stop superiority begins to irritate; you begin to wonder about the standards that make him so certain he is always right. He asserts that the scientist, unlike the crank, does his best to remain open-minded. So how can he be so sure that no sane person has ever seen a flying saucer, or used a dowsing rod to locate water? And that all the people he disagrees with are unbalanced fanatics? A colleague of the positivist philosopher A. J. Ayer once remarked wryly "I wish I was as certain of anything as he seems to be about everything". Martin Gardner produces the same feeling."

"To make our position clearer, we may formulate it in another way. Let us call a proposition which records an actual or possible observation an experiential proposition. Then we may say that it is the mark of a genuine factual proposition, not that it should be equivalent to an experiential proposition, or any finite number of experiential propositions, but simply that some experiential propositions can be deduced from it in conjunction with certain other premises without being deducible from those other premises alone."

""I exist" does not follow from "there is a thought now." The fact that a thought occurs at a given moment does not entail that any other thought has occurred at any other moment, still less that there has occurred a series of thoughts sufficient to constitute a single self. As Hume conclusively showed, no one event intrinsically points to any other. We infer the existence of events which we are not actually observing, with the help of general principle. But these principles must be obtained inductively. By mere deduction from what is immediately given we cannot advance a single step beyond. And, consequently, any attempt to base a deductive system on propositions which describe what is immediately given is bound to be a failure."

"The problem of induction is, roughly speaking, the problem of finding a way to prove that certain empirical generalizations which are derived from past experience will hold good also in the future. There are only two ways of approaching this problem on the assumption that it is a genuine problem, and it is easy to see that neither of them can lead to its solution."

"The principles of logic and mathematics are true simply because we never allow them to be anything else. And the reason for this is that we cannot abandon them without contradicting ourselves, without sinning against the rules which govern the use of language, and so making our utterances self-stultifying. In other words, the truths of logic and mathematics are analytic propositions or tautologies."

"If now I…say "Stealing money is wrong," I produce a sentence which has no factual meaning — that is, expresses no proposition which can be either true or false. It is as if I had written "Stealing money!!" — where the shape and thickness of the exclamation marks show, by a suitable convention, that a special sort of moral disapproval is the feeling which is being expressed."

"To say that authority, whether secular or religious, supplies no ground for morality is not to deny the obvious fact that it supplies a sanction."

"While moral rules may be propounded by authority the fact that these were so propounded would not validate them."

"The ground for taking ignorance to be restrictive of freedom is that it causes people to make choices which they would not have made if they had seen what the realization of their choices involved."

"Ayer’s central mistake was to think that his principle could distinguish between the meaningful and meaningless. This error has two parts. First, a better distinction would be between the objective and subjective. … The second part of the mistake is to make the distinction binary where it should be spectral. … Ayer found himself caught in a classic philosophical predicament. If an idea is too vague it will be dismissed as woolly and hand-waving. Too precise, however, and the logic-choppers will be out to unpick its contradictions and inconsistencies. As Aristotle’s immortal adage states, ‘It is the mark of the trained mind never to expect more precision in the treatment of any subject than the nature of that subject permits’ – nor less, we might add. The Goldilocks state of philosophy is to be precise enough to be saying something substantive but not so precise as to ride roughshod over the complexities and ambiguities of the real world."

"Friends were anxious to learn if I had had a near-death experience, and if so, what effect it had had on my longstanding public atheism. Had I had an epiphany? Was I going to follow in the footsteps of Ayer (who recovered his aplomb and insisted a few days later "what I should have said is that my experiences have weakened, not my belief that there is no life after death, but my inflexible attitude towards that belief"), or was my atheism still intact and unchanged? Yes, I did have an epiphany. I saw with greater clarity than ever before in my life that when I say "Thank goodness!" this is not merely a euphemism for "Thank God!" (We atheists don't believe that there is any God to thank.) I really do mean thank goodness! There is a lot of goodness in this world, and more goodness every day, and this fantastic human-made fabric of excellence is genuinely responsible for the fact that I am alive today. It is a worthy recipient of the gratitude I feel today, and I want to celebrate that fact here and now."

"He was the antithesis of the philosopher of mystery and intimation, and he was not tempted to technicality. He lived assertively and was vain and cocksure — at some cost to his philosophical reputation, since other philosophers were as human in their judgements on him. He was also honest, humane, and more or less on the Left in politics. He liked society, was a man of many women, came to be self-judging, and after some sadness died bravely, on 27 June 1989."

"He was undoubtedly one of the liveliest figures on the British philosophical scene in his time and, when he appeared on it, it was in need of enlivening. He was not a highly original thinker. His impact was due to the brilliance with which he arranged and expressed the ideas he had acquired from others. Perhaps his greatest intellectual virtue was his unremitting adherence to clarity and to rational argument. His work is without allusions, undeveloped suggestions, obscurity, and mannerism. Through his books and his teaching he sets a fine example of intellectual discipline."

"In seeking to refound philosophy as an analytic discipline, Ayer was not just trying to separate philosophy from life but to liberate life from philosophy. As he saw it, philosophers had traditionally set out to establish themselves as authorities on the fundamental nature of the universe and the character of right and wrong. They posited immutable laws of nature, claimed to show that the world was one, or pretended to demonstrate the existence of supersensible realms of being; they invented gods, divine commands and human ends, and sought in that way to tell people how to live. To Ayer all this was not only unjustified — talk of supernatural reality, of beings existing outside space and time, or of the fundamental unity of things was literally senseless — but also reactionary. In narrowing the possibilities of experience, in placing limits on the findings of science and in dictating what was right and wrong, philosophy had become a cramping distorting discipline. The promise of life after death, the conception of earthly life as representing a punishment for inherited sin, the belief that pleasure was evil, had terribly oppressive effects. With metaphysics banished, science could develop unfettered, and people would become more experimental, more open to other points of view, more tolerant in thought and practice. They would, in particular, become less likely to engage in religious and ideological wars. Above all else, Ayer hoped, men and women would realise that this life was the only life they have, and would thus become more appreciative of what it had to offer. Which is where the football, the dancing and the love affairs come in."

"Freddie became so much nicer after he died. He was not nearly so boastful. He took an interest in other people."

"There is philosophy, which is about conceptual analysis — about the meaning of what we say — and there is all of this … all of life."

"I am using the word "perceive". I am using it here in such a way that to say of an object that it is perceived does not entail saying that it exists in any sense at all. And this is a perfectly correct and familiar usage of the word. If there is thought to be a difficulty here, it is perhaps because there is also a correct and familiar usage of the word "perceive", in which to say of an object that it is perceived does carry the implication that it exists."

"No moral system can rest solely on authority."

"I see philosophy as a fairly abstract activity, as concerned mainly with the analysis of criticism and concepts, and of course most usefully of scientific concepts."

"There never comes a point where a theory can be said to be true. The most that one can claim for any theory is that it has shared the successes of all its rivals and that it has passed at least one test which they have failed."

"It seems that I have spent my entire time trying to make life more rational and that it was all wasted effort."

"I saw a Divine Being. I'm afraid I'm going to have to revise all my various books and opinions."

"I suddenly stopped and looked out at the sea and thought, my God, how beautiful this is … for 26 years I had never really looked at it before."

"The traditional disputes of philosophers are, for the most part, as unwarranted as they are unfruitful. The surest way to end them is to establish beyond question what should be the purpose and method of a philosophical enquiry. And this is by no means so difficult a task as the history of philosophy would lead one to suppose. For if there are any questions which science leaves it to philosophy to answer, a straightforward process of elimination must lead to their discovery."

"The criterion which we use to test the genuineness of apparent statements of fact is the criterion of verifiability. We say that a sentence is factually significant to any given person, if, and only if, he knows how to verify the proposition which it purports to express — that is, if he knows what observations would lead him, under certain conditions, to accept the proposition as being true, or reject it as being false."

"The study of Ethics would, no doubt, be far more simple, and its results far more "systematic," if, for instance, pain were an evil of exactly the same magnitude as pleasure is a good; but we have no reason whatever to assume that the Universe is such that ethical truths must display this kind of symmetry ... ."

"I can prove now, for instance, that two human hands exist. How? By holding up my two hands, and saying, as I make a certain gesture with the right hand, "Here is one hand," and adding, as I make a certain gesture with the left, "and here is another." And if, by doing this, I have proved ipso facto the existence of external things, you will all see that I can also do it now in numbers of other ways: there is no need to multiply examples."

"It is raining but I do not believe that it is."

"G. E. Moore (1942) noted it is pragmatically incoherent to assert, 'It is raining but I don't believe that it is'."

"By far the most valuable things, which we know or can imagine, are certain states of consciousness, which may roughly be described as the pleasures of human intercourse and the enjoyment of beautiful objects. No one, probably, who has asked himself the question, has ever doubted that personal affection and the appreciation of what is beautiful in Art or Nature, are good in themselves; nor, if we consider strictly what things are worth having purely for their own sakes, does it appear probable that any one will think that anything else has nearly so much value as the things which are included under these two heads."

"Though the easiest popular way of practically refuting … any Fallacy is, by bringing forward a parallel case, where it leads to a manifest absurdity, a metaphysical objection may still be urged against many cases in which we thus reason from calculation of chances; an objection not likely indeed practically to influence any one, but which may afford the Sophist a triumph over those who are unable to find a solution."

"On the whole, the arguments which it requires the greatest nicety of art to refute effectually … are those which are so very weak and silly that it is difficult to make their absurdity more palpable than it is already.… The task reminds one of the well-known difficult feat of cutting through a cushion with a sword."

"There is, I conceive, no point in which the idea of dishonest artifice is in most people's minds so intimately associated with that of Rhetoric, as the address to the Feelings or Active Principles of our nature. This is usually stigmatized as "an appeal to the Passions instead of the Reason;" as if Reason alone could ever influence the Will, and operate as a motive, which it no more can, than the eyes, which show a man his road, can enable him to move from place to place; or than a ship provided with a compass, can sail without a wind."

"Of Rhetoric various definitions have been given by different writers; who, however, seem not so much to have disagreed in their conceptions of the nature of the same thing, as to have had different things in view while they employed the same term."

"He that is not aware of his ignorance, will be only misled by his knowledge."

"In the present day, however, the province of Rhetoric, in the widest acceptation that would reckoned admissible, comprehends all "Composition in Prose;" in the narrowest sense, it would be limited to "Persuasive Speaking.""

"Cicero is hardly to be reckoned … for he delighted so much more in the practice, than in the theory, of his art, that he is perpetually drawn off from the rigid philosophical analysis of its principles, into discursive declamations, always eloquent indeed, and often highly interesting, but adverse to regularity of system, and frequently as unsatisfactory to the practical student as to the Philosopher."

"Concerning the utility of Rhetoric, it is to be observed that it divides itself into two; first, whether Oratorical skill be, on the whole, a public benefit, or evil; and secondly, whether any artificial system of Rules is conducive to the attainment of that skill."

"No one complains of the rules of Grammar as fettering Language; because it is understood that correct use is not founded on Grammar, but Grammar on correct use. A just system of Logic or of Rhetoric is analogous, in this respect, to Grammar.."

"It would be difficult to find a better instance of that favourite maxim of our grandfathers that "the pen is mightier than the sword," than the effect upon British institutions of the uneventful life of Jeremy Bentham, a shy recluse of unimpressive speech and appearance, who was so little of a politician that even in 1817 he was not prosecuted for publishing his highly "seditious" Reform Catechism in favour of household suffrage. Born in 1748, and dying in 1832 just when his principles were beginning to invade the seats of power, he was never the man of the moment, but his influence was a force in history during more than a hundred years. As early as 1776...young Bentham's Fragment on Government also appeared. It challenged the legal doctrine of the age, sanctioned by Blackstone himself, that law was a fixed and authoritative science and the British Constitution perfect. Bentham, on the other hand, proclaimed both law and politics to be perpetual experiments in the means of promoting "utility" or happiness."

"Priestley was the first (unless it was Beccaria) who taught my lips to pronounce this sacred truth — that the greatest happiness of the greatest number is the foundation of morals and legislation."

"Create all the happiness you are able to create: remove all the misery you are able to remove. Every day will allow you to add something to the pleasure of others, or to diminish something of their pains. And for every grain of enjoyment you sow in the bosom of another, you shall find a harvest in your own bosom; while every sorrow which you pluck out from the thoughts and feelings of a fellow creature shall be replaced by beautiful peace and joy in the sanctuary of your soul."

"To what shall the character of utility be ascribed, if not to that which is a source of pleasure?"

"It is part of a work to which if ever it should be completed I intend to give some such title as Principles of Legal Policy; the object of it is to trace out a new model for the Laws: of my own country you may imagine, in the first place: but keeping those of other countries all along in view. To ascertain what the Laws ought to be, in form and tenor as well as in matter: and that elsewhere as well as here. All that I shall say to recommend it to you is that I have taken counsel of you much oftener than of our own Ld. Coke and Hale and Blackstone. The repose of Grotius and Puffendorf and Barbeyrac and Burlamaqui I would never wish to see disturbed. I have built solely on the foundation of utility, laid as it is by Helvetius. Becarria has been lucrative pedibus, or if you please manibus, meis."