In this third period (as it may be termed) of my mental progress, which now went hand in hand with hers, my opinions gained equally in breadth and depth, I understood more things, and those which I had understood before, I now understood more thoroughly. I had now completely turned back from what there had been of excess in my reaction against Benthamism. I had, at the height of that reaction, certainly become much more indulgent to the common opinions of society and the world, and more willing to be content with seconding the superficial improvement which had begun to take place in those common opinions, than became one whose convictions on so many points, differed fundamentally from them. I was much more inclined, than I can now approve, to put in abeyance the more decidedly heretical part of my opinions, which I now look upon as almost the only ones, the assertion of which tends in any way to regenerate society.

He is a dreamer of ancient times, or rather, of the myths of what ancient times used to be. Such men are harmless in themselves, but their queer lack of realism makes them fools for others.

What is at stake here is precisely the problem of the fulfillment of desire: when we encounter in reality an object which has all the properties of the fantasized object of desire, we are nevertheless necessarily somewhat disappointed; we experience a certain this is not it; it becomes evident that the finally found real object is not the reference of desire even though it possesses all the required properties.

The analysis achieves its end when the patient is able to recognize, in the Real of his symptom, the only support of his being. That is how we must read Freud's 'wo we war, soll ich werden:' you, the subject, must identify yourself with the place where your symptom already was; in its pathological particularity you must recognize the element which gives consistency to your being.

Those who try to include all life when trying to determine justice: Should a man be executed for killing a fly? No? The fly has a short life span? The fly is small? All these rationalizations can be applied to you, by a creature that lives longer, is bigger, etc. #philosophy 

Scientific revolutions are inaugurated by a growing sense... that an existing paradigm has ceased to function adequately in the exploration of an aspect of nature to which that paradigm itself had previously led the way. p. 91

The subject of a gestalt demonstration knows that his perception has shifted because he can make it shift back and forth repeatedly while he holds the same book or piece of paper in his hands. Aware that nothing in his environment has changed, he directs his attention increasingly not to the figure (duck or rabbit) but to the lines of the paper he is looking at. Ultimately he may even learn to see those lines without seeing either of the figures, and he may then say (what he could not legitimately have said earlier) that it is these lines that he really sees but that he sees them alternately as a duck and as a rabbit. ...As in all similar psychological experiments, the effectiveness of the demonstration depends upon its being analyzable in this way. Unless there were an external standard with respect to which a switch of vision could be demonstrated, no conclusion about alternate perceptual possibilities could be drawn. p. 114 (3rd edn.)

These examples point to the third and most fundamental aspect of the incommensurability of competing paradigms. In a sense that I am unable to explicate further, the proponents of competing paradigms practice their trades in different worlds. One contains constrained bodies that fall slowly, the other pendulums that repeat their motions again and again. In one, solutions are compounds, in the other mixtures. One is embedded in a flat, the other in a curved, matrix of space. Practicing in different worlds, the two groups of scientists see different things when they look from the same point in the same direction. Again, that is not to say that they can see anything they please. Both are looking at the world, and what they look at has not changed. But in some areas they see different things, and they see them in different relations one to the other. That is why a law that cannot even be demonstrated to one group of scientists may occasionally seem intuitively obvious to another. p. 149

We may, to be more precise, have to relinquish the notion, explicit or implicit, that changes of paradigm carry scientists and those who learn from them closer and closer to the truth.

By now it may be clear that the position I'm developing is a sort of post-Darwinian Kantianism.

Only when they must choose between competing theories do scientists behave like philosophers.

I suggest that scientific knowledge, though logically more articulate and far more complex, is of this sort. The books and teachers from whom it is acquired present concrete examples together with a multitude of theoretical generalizations. Both are essential carriers of knowledge, and it is therefore Pickwickian to seek a methodological criterion that supposes the scientist can specify in advance whether each imaginable instance fits or would falsify his theory.

To my complete surprise, that exposure to out-of-date scientific theory and practice radically undermined some of my basic conceptions about the nature of science and the reasons for its special success.Those conceptions were ones I had previously drawn partly from scientific training itself and partly from a long-standing avocational interest in the philosophy of science. Somehow, whatever their pedagogic utility and their abstract plausibility, those notions did not at all fit the enterprise that historical study displayed. Yet they were and are fundamental to many discussions of science, and their failures of verisimilitude therefore seemed thoroughly worth pursuing. The result was a drastic shift in my career plans, a shift from physics to history of science and then, gradually, from relatively straightforward historical problems back to the more philosophical concerns that had initially led me to history.

Somehow, the practice of astronomy, physics, chemistry or biology normally fails to evoke the controversies over fundamentals that today seem endemic among, say, psychologists or sociologists. Attempting to discover the source of that difference led me to recognize the role in scientific research of what I have since called "paradigms." These I take to be universally recognized scientific achievements that for a time provide model problems and solutions for a community of practitioners.

History, if viewed as a repository for more than anecdote or chronology, could produce a decisive transformation in the image of science by which we are now possessed.

Out-of-date theories are not in principle unscientific because they have been discarded. That choice, however, makes it difficult to see scientific development as a process of accretion.

Normal science, the activity in which most scientists inevitably spend almost all their time, is predicated on the assumption that the scientific community knows what the world is like. Normal science often suppresses fundamental novelties because they are necessarily subversive of its basic commitments.

"Normal science" means research firmly based upon one or more past scientific achievements, achievements that some particular scientific community acknowledges for a time as supplying the foundation for its further practice.

Men whose research is based on shared paradigms are committed to the same rules and standards for scientific practice. That commitment and the apparent consensus it produces are prerequisites for normal science, i.e., for the genesis and continuation of a particular research tradition.

Ever since prehistoric antiquity one field of study after another has crossed the divide between what the historian might call its prehistory as a science and its history proper. These transitions to maturity have seldom been so sudden or so unequivocal as my necessarily schematic discussion may have implied. But neither have they been historically gradual, coextensive, that is to say, with the entire development of the fields within which they occurred.

Few people who are not actually practitioners of a mature science realize how much mop-up work of this sort a paradigm leaves to be done or quite how fascinating such work can prove in the execution.

These three classes of problems-determination of significant fact, matching of facts with theory, and articulation of theory-exhaust, I think, the literature of normal science, both empirical and theoretical. They do not, of course, quite exhaust the entire literature of science. There are also extraordinary problems, and it may well be their resolution that makes the scientific enterprise as a whole so particularly worthwhile. But extraordinary problems are not to be had for the asking. They emerge only on special occasions prepared by the advance of normal research.

The scientific enterprise as a whole does from time to time prove useful, open up new territory, display order, and test long-accepted belief. Nevertheless, the individual engaged on a normal research problem is almost never doing any one of these things. Once engaged, his motivation is of a rather different sort. What then challenges him is the conviction that, if only he is skillful enough, he will succeed in solving a puzzle that no one before has solved or solved so well.

Scientists work from models acquired through education and through subsequent exposure to the literature often without quite knowing or needing to know what characteristics have given these models the status of community paradigms.

Normal science, the puzzle-solving activity we have just examined, is a highly cumulative enterprise, eminently successful in its aim, the steady extension of the scope and precision of scientific knowledge. In all these respects it fits with great precision the most usual image of scientific work. Yet one standard product of the scientific enterprise is missing. Normal science does not aim at novelties of fact or theory and, when successful, finds none.

We must now ask how changes of this sort can come about, considering first discoveries, or novelties of fact, and then inventions, or novelties of theory. That distinction between discovery and invention or between fact and theory will, however, immediately prove to be exceedingly artificial.

In science, as in the playing card experiment, novelty emerges only with difficulty, manifested by resistance, against a background provided by expectation.

In the development of any science, the first received paradigm is usually felt to account quite successfully for most of the observations and experiments easily accessible to that science's practitioners. Further development, therefore, ordinarily calls for the construction of elaborate equipment, the development of an esoteric vocabulary and skills, and a refinement of concepts that increasingly lessens their resemblance to their usual common-sense prototypes. That professionalization leads, on the one hand, to an immense restriction of the scientist's vision and to a considerable resistance to paradigm change. The science has become increasingly rigid. On the other hand, within those areas to which the paradigm directs the attention of the group, normal science leads to a detail of information and to a precision of the observation-theory match that could be achieved in no other way.

Philosophers of science have repeatedly demonstrated that more than one theoretical construction can always be placed upon a given collection of data. History of science indicates that, particularly in the early developmental stages of a new paradigm, it is not even very difficult to invent such alternates. But that invention of alternates is just what scientists seldom undertake except during the pre-paradigm stage of their science's development and at very special occasions during its subsequent evolution. So long as the tools a paradigm supplies continue to prove capable of solving the problems it defines, science moves fastest and penetrates most deeply through confident employment of those tools. The reason is clear. As in manufacture so in science-retooling is an extravagance to be reserved for the occasion that demands it. The significance of crises is the indication they provide that an occasion for retooling has arrived.

The habits of study acquired at Universities are of the highest importance in after-life. At the season when you are in young years the whole mind is, as it were, fluid, and is capable of forming itself into any shape that the owner of the mind pleases to order it to form itself into. The mind is in a fluid state, but it hardens up gradually to the consistency of rock or iron, and you cannot alter the habits of an old man, but as he has begun he will proceed and go on to the last.

What the Universities have mainly done-what I have found the University did for me, was that it taught me to read in various languages and various sciences, so that I could go into the books that treated of these things, and try anything I wanted to make myself master of gradually, as I found it suit me. Whatever you may think of all that, the clearest and most imperative duty lies on every one of you to be assiduous in your reading; and learn to be good readers, which is, perhaps, a more difficult thing than you imagine. Learn to be discriminative in your reading-to read all kinds of things that you have an interest in, and that you find to be really fit for what you are engaged in.

If you are in a strait, a very good indication as to choice-perhaps the best you could get-is a book you have a great curiosity about. You are then in the readiest and best of all possible conditions to improve by that book.

Books-there is a good kind of a book and a bad kind of a book. I am not to assume that you are all ill acquainted with this; but I may remind you that it is a very important consideration at present. It casts aside altogether the idea that people have that if they are reading any book-that if an ignorant man is reading any book, he is doing rather better than nothing at all.

The most remarkable piece of reading that you may be recommended to take and try if you can study is a book by Goethe-one of his last books, which he wrote when he was an old man, about seventy years of age-I think one of the most beautiful he ever wrote, full of mild wisdom, and which is found to be very touching by those who have eyes to discern and hearts to feel it. It is one of the pieces in "Wilhelm Meister's Travels." I read it through many years ago; and, of course, I had to read into it very hard when I was translating it (applause), and it has always dwelt in my mind as about the most remarkable bit of writing that I have known to be executed in these late centuries. I have often said, there are ten pages of that which, if ambition had been my only rule, I would rather have written than have written all the books that have appeared since I came into the world.

I warmly second the advice of the wisest of men-"Don't be ambitious; don't be at all too desirous to success; be loyal and modest." Cut down the proud towering thoughts that you get into you, or see they be pure as well as high. There is a nobler ambition than the gaining of all California would be, or the getting of all the suffrages that are on the planet just now.

If you find many people who are hard and indifferent to you in a world that you consider to be unhospitable and cruel-as often, indeed, happens to a tender-hearted, stirring young creature-you will also find there are noble hearts who will look kindly on you, and their help will be precious to you beyond price.

The force that had been lent my father he honorably expended in manful well-doing. A portion of this planet bears beneficent traces of his strong hand and strong head. Nothing that he undertook to do but he did it faithfully and like a true man. I shall look on the houses he built with a certain proud interest. They stand firm and sound to the heart all over his little district.

Nay, am not I also the humble James Carlyle's work? I owe him much more than existence, I owe him a noble inspiring example (now that I can read it in that rustic character). It was he exclusively that determined on educating me; that from his small hard-earned funds sent me to school and college, and made me whatever I am or may become. Let me not mourn for my father, let me do worthily of him. So shall he still live even here in me, and his worth plant itself honorably forth into new generations.

This great maxim of philosophy he had gathered by the teaching of nature alone - that man was created to work, not to speculate or feel or dream. Accordingly, he set his whole heart thitherwards. He did work wisely and unweariedly, and perhaps performed more with the tools he had than any man I now know.

He seldom or never spoke except actually to convey an idea. Measured by quantity of words, he was a talker of fully average copiousness; by extent of meaning communicated, he was the most copious I have listened to. How in few sentences he would sketch you off an entire biography, an entire object or transaction, keen, clear, rugged, genuine, completely rounded In! His words came direct from the heart by the inspiration of the moment.

On the whole, ought I not to rejoice that God was pleased to give me such a father; that from earliest years I had the example of a real man of God's own making continually before me? Let me learn of him. Let me write my books as he built his houses, and walk as blamelessly through this shadow world; if God so will, to rejoin him at last. Amen.

Alas! such is the miseducation of these days, it is only among those that are called the uneducated classes - those educated by experience - that you can look for a Man. Even among these, such a sight is growing daily rarer. My father, in several respects, has not, that I can think of, left his fellow. Perhaps among Scottish peasants what Samuel Johnson was among English authors. I have a sacred pride in my peasant father, and would not exchange him, even now, for any king known to me. Gold and the guinea stamp - the Man and the clothes of the man. Let me thank God for that greatest of blessings, and strive to live worthily of it.

The more I reflect on it, the more I must admire how completely nature had taught him; how completely he was devoted to his work, to the task of his life, and content to let all pass by unheeded that had not relation to this. It is a singular fact, for example, that though a man of such openness and clearness, he had never, I believe, read three pages of Burns's poems. Not even when all about him became noisy and enthusiastic, I the loudest, on that matter, did he feel it worth while to renew his investigation of it, or once turn his face towards it. The poetry he liked (he did not call it poetry) was truth, and the wisdom of reality. Burns, indeed, could have done nothing for him. As high a greatness hung over his world as over that of Burns - the ever-present greatness of the Infinite itself. Neither was he, like Burns, called to rebel against the world, but to labor patiently at his task there, uniting the possible with the necessary to bring out the real, wherein also lay an ideal.

I knew Robert Burns, and I knew my father. Yet were you to ask me which had the greater natural faculty, I might perhaps actually pause before replying. Burns had an infinitely wider education, my father a far wholesomer. Besides, the one was a man of musical utterance; the other wholly a man of action, with speech subservient thereto. Never, of all the men I have seen, has one come personally in my way in whom the endowment from nature and the arena from fortune were so utterly out of all proportion. I have said this often, and partly know it. As a man of speculation - had culture ever unfolded him - he must have gone wild and desperate as Burns; hut he was a man of conduct, and work keeps all right. What strange shapable creatures we are!

My father's education was altogether of the worst and most limited. I believe he was never more than three months at any school. What he learned there showed what he might have learned. A solid knowledge of arithmetic, a fine antique handwriting - these, with other limited practical etceteras, were all the things he ever heard mentioned as excellent. He had no room to strive for more.

But greatly his most important culture he had gathered - and this, too, by his own endeavors - from the better part of the district, the religious men; to whom, as to the most excellent, his own nature gradually attached and attracted him. He was religious with the consent of his whole faculties. Without religion he would have been nothing.

Complete, at the same time, was his confidence in his own judgment when it spoke to him decisively. He was one of those few that could believe and know as well as inquire and be of opinion. When I remember how much he admired intellectual force, how much he had of it himself, and yet how unconsciously and contentedly he gave others credit for superiority, I again see the healthy spirit of the genuine man.

I think he once told us his first short clothes were a hull made mostly or wholly of leather. We all only laughed, for it is now long ago. Thou dear father! Through what stern obstructions was thy way to manhood to be forced, and for us and for our travelling to be made smooth!

Had there not been a natural goodness and indestructible force in my father, I see not how be could have bodied himself forth from these mean impediments. I suppose good precepts were not wanting. There was the Bible to read. Old John Orr, the schoolmaster, used from time to time to lodge with them; be was religious and enthusiastic (though in practice irregular with drink). In my grandfather, also, there seems to have been a certain geniality; for instance, he and a neighbor, Thomas Hogg, read "Anson's Voyages;" also tho "Arabian Nights," for which latter my father, armed with zealous conviction, scrupled not to censure them openly. By one means and another, at an early age he had acquired principles, lights that not only flickered, but shone steadily to guide his way.

It must have been in his teens, perhaps rather early, that he and his elder brother John, with William Bell (afterwards of Wylie Hill, and a noted drover) and his brother, all met in the kiln at Eelief to play cards. The corn was dried then at home. There was a fire, therefore, aud perhaps it was both heat and light. The boys had played, perhaps, often enough for trifling stakes, and always parted in good humor. One night they came to some disagreement. My father spoke out what was in him about the folly, the sinfulness, of quarreling over a perhaps sinful amusement. The earnest mind persuaded other minds. They threw the cards into the fire, and (I think the younger Bell told my brother James) no one of the four ever touched a card again through life. My father certainly never hinted at such a game since I knew him. I cannot remember that I, at that age, had any such force of belief. Which of us can?