debate, debate, debate

debate is on my mind.

1. I found an interesting journal over the weekend titled Debates in Neuroscience. It appears to be a very new journal, the article I’m halfway through (a critical look at adult neurogenesis) was accepted in Februray of this year.

The vision that led to the establishment of this journal is to provide a forum for the neuroscience community that is devoted explicitly to controversies and conflicting ideas. We are very grateful to Dr. Norman M. Weinberger who first presented the idea for this journal to us. The give and take of debate and controversy are critical to enabling conceptual advances within any field of science, but these normally take place at scientific meetings, informal discussions, or in private correspondence. Debates in Neuroscience makes the exposition of emerging debates and controversies its centerpiece.

Since the purpose of most neuroscience journals is publishing new research reports and/or review papers, and compounded by the unusual breadth of neuroscience, there is an unmet need on the part of researchers, instructors, trainees, and students to access relevant alternate viewpoints on topics of interest, especially outside their own areas of specialization. Each issue of Debates in Neuroscience will focus on a small number of controversial topics. Each topic will be addressed by two or more papers written by nominated authors. The papers will provide an in-depth exposition of an alternative theoretical or conceptual perspective. Authors will subsequently have an opportunity to respond to the rival viewpoints.

2. There was a debate on whether we are better off without religion at Westminster this past week.

Speaking for the motion, “We’d be better off without religion”, at a debate held in Westminster on March 27; Professor Richard Dawkins, Professor A.C. Grayling and Christopher Hitchens. Speaking against: Rabbi Julia Neuberger, Professor Roger Scruton and Nigel Spivey. The debate was chaired by Joan Bakewell

You can listen to a podcast of the debate by pointing your browser here.

3. I discovered I had been linked to on A Don’s Life blog for a history carnival. While I did not submit my blurb on Andrew Scull’s review of History of Madness to the carnival, I must say I was flattered to have a Professor at Cambridge read and link to the post. Nonetheless, Professor Beard’s characterization of me prematurely dancing on Foucault’s grave was a little exaggerated. I will certainly read the newly translated edition in one hand (my copy of Madness and Civilization in the other) and decide then whether or not to put on my dancing shoes. I’d rather chalk up the tone I took in my post to the excitement of taking the shoes out of the closet.

excerpt from santiago ramon y cajal’s advice for a young investigator

Concentration

Those writing about logic emphasize with good reason the creative power of concentration, although they tend to ignore a variety that might appropriately be called cerebral polarization or sustained concentration—that is, steady orientation of all our faculties toward a single object of study for a period of months or even years. The thinking of countless brilliant minds ends up sterile for lack of this ability, which the French call esprit de suite. I could cite dozens of Spaniards with minds finely suited to scientific investigation who retreat discouraged from a problem without seriously measuring their strength, perhaps just at the moment when nature was about to reward their eagerness with the anxiously awaited revelation. Our classrooms and laboratories are full of these capricious and restless souls who love research and suffer through mishaps with the retort or microscope day after day. Their feverish activity yields an avalanche of lectures, articles, and books—upon which they have lavished a great deal of scholarship and talent. They constantly exhort the garrulous throng of dreamers and theorizers with the indispensable need for observing nature directly. Then, after long years of publicity and experimental work, those closest to them (their satellites at the prestigious yet mysterious meetings where the great preside) are asked about the discoveries of the master. The allies are forced to confess shamefacedly that the great burden of talent, combined with the virtual impossibility of summarizing in a nutshell the extraordinary magnitude and range of the work undertaken, make it impossible to state what partial or positive progress had been made. These are the inevitable fruits of negligence or excessive lack of focus, not to mention childish, encyclopedic ostentation. This approach is inconceivable today, when even the most renowned scholars specialize and concentrate in order to produce. But enough of this; we shall deal later with bad habits of the will.
To bring scientific investigation to a happy end once appropriate methods have been determined, we must hold firmly in mind the goal of the project. The object here is to focus the train of thought on more and more complex and accurate associations between images based on observation and ideas slumbering in the unconscious—ideas that only vigorous concentration of mental energy can raise to the conscious level. One must achieve total absorption; expectation and focused attention are not enough. We must take advantage of all lucid moments, whether they occur during the meditation following prolonged rest; during the super-intense mental work nerve cells achieve when fired by concentration; or during scientific discussion, whose impact often generates unanticipated intuition like sparks from steel. Most people who lack self-confidence are unaware of the marvelous power of prolonged concentration. This type of cerebral polarization (which involves a special ordering of perceptions) refines judgment, enriches analytical powers, spurs constructive imagination, and—by focusing all light of reason on the darkness of a problem—allows unforseen and subtle relationships to be discovered. If a photographic plate under the center of a lens focused on the heavens is exposed for hours, it comes to reveal stars so far away that even the most powerful telescopes fail to reveal them to the naked eye. In a similar way, time and concentration allow the intellect to perceive a ray of light in the darkness of the most complex problem.

The comparison just made is not, however, entirely accurate. Photography in astronomy is limited to recording faint though preexisting stars, whereas intellectual work is an act of creation. It is as if the mental image that is studied over a period of time were to sprout appendages like an ameba— outgrowths that extend in all directions while avoiding one obstacle after another—before interdigitating with related ideas.

The forging of new truth almost always requires severe abstention and renunciation. During the so-called intellectual incubation period, the investigator should ignore everything unrelated to the problem of interest, like a somnambulist attending only to the voice of the hypnotist. In the lecture room, on walks, in the theater, in conversation, and even in reading for pleasure, seek opportunities for insight, comparisons, and hypotheses that add at least some clarity to the problem one is obsessed with. Nothing is useless during this process of adjustment. The first glaring errors, as well as the wrong turns ventured on by the imagination, are necessary because in the end they lead us down the correct path. They are part of the final success, just as the initial formless sketches of the artist are a part of the finished portrait.

When one reflects on the ability that humans display for modifying and refining mental activity related to a problem under serious examination, it is difficult to avoid concluding that the brain is plastic and goes through a process of anatomical and functional differentiation, adapting itself progressively to the problem. The adequate and specific organization acquired by nerve cells eventually produces what I would refer to as professional or adaptational talent. As a motivator of the will itself, this brain organization provides the energy to adapt understanding to the nature of the problem under consideration. In a certain sense, it would not be paradoxical to say that the person who initiates the solution to a problem is different from the one who solves it. This is an obvious and simple explanation for the astonishment proclaimed by all investigators on discovering the simple solution so laboriously sought. “Why didn’t I think of this at the outset!” we exclaim. “There was so much confusion traveling down roads that led nowhere!”

If a solution fails to appear after all of this, and yet we feel success is just around the corner, try resting for a while. Several weeks of relaxation and quiet in the countryside brings calmness and clarity to the mind. Like the early morning frost, this intellectual refreshment withers the parasitic and nasty vegetation that smothers the good seed. Bursting forth at last is the flower of truth, whose calyx usually opens after a long and profound sleep at dawn—in those placid hours of the morning that Goethe and so many others consider especially favorable for discovery.

Travel has the same virtue of renewing thought and dissipating tiring preoccupations by furnishing new views of the world and transmitting our store of ideas to others. How often the powerful vibration of the locomotive and the spiritual solitude of the railway car (the “just rewards of humanity,” as Descartes might say) suggest ideas that are ultimately confirmed in the laboratory!

Now that scientific research has become a regular profession on the payroll of the state, the observer can no longer afford to concentrate for extended periods of time on one subject, and must work even harder. Gone are the wonderful days of yore when those curious about nature were able to remain withdrawn in the silence of the study, confident that rivals would not disrupt their tranquil meditations. Research is now frantic. When a new technique is outlined, many scholars immediately take advantage of it and apply it almost simultaneously to the same problems—diminishing the glory of the originator, who probably lacks the facilities and time necessary to gather all the fruits of his labors, and of his lucky star.

As a result, the coincidences and battles of priority are inevitable. It is clear that once an idea becomes public it joins the intellectual atmosphere that nourishes all of our minds. Because of the functional synchronization that governs minds prepared and oriented toward a particular subject, the new idea is assimilated simultaneously in Paris and Berlin, in London and Vienna—in virtually the same way, with similar developments and applications. The discovery grows and develops spontaneously and automatically like an organism, as though scholars are reduced to mere cultivators of the seed planted by a genius. The magnificent flowering of new information is observed by all, and naturally everyone wishes to gather for themselves the splendid blossoms. This explains the eagerness to publish most laboratory studies, even when imperfect and incomplete. The desire to arrive first results at times in shallowness, although it is also true that feverish anxiety to reach the goal first wins the prize for priority.

Be that as it may, it is unwise to become disenchanted if someone arrives ahead of us. Continue work undaunted; in time our turn will come. That eminent woman, Madam Curie, provides an eloquent example of untiring perseverance. After discovering the radioactivity of thorium, she was unpleasantly surprised to learn that the same observation had been announced a short time earlier by Schmidt in the Wiedermann Annalen. Far from disheartened, however, she continued her research uninterrupted. She analyzed new substances with the electroscope, including uranium oxide (pitchblende) from the mines of Johann Georgenstadt, and its radioactivity proved four times stronger than that of uranium itself. Suspecting that this very active material contained a new element, she undertook (with the assistance of M. Curie) a series of ingenious, patient, and heroic experiments that were rewarded with the discovery of a new element, the remarkable radium. Its properties inspired a great deal of further work that has revolutionized chemistry and physics.

In Spain, where laziness is a religion rather than a vice, there is little appreciation for how the monumental work of German chemists, naturalists, and physicians is accomplished—especially when it would appear that the time required to execute the plan and assemble a bibliography might involve decades! Yet these books have been written in a year or two, quietly and without feverish haste. The secret lies in the method of work; in taking advantage of as much time as possible for the activity; in not retiring for the day until at least two or three hours are dedicated to the task; in wisely constructing a dike in front of the intellectual dispersion and waste of time required by social activity; and finally, in avoiding as much as possible the malicious gossip of the café and other entertainment—which squanders our nervous energy (sometimes even causing disgust) and draws us away from our main task with childish conceits and futile pursuits.
If our professions do not allow us to devote more than two hours a day to a subject, do not abandon the work on the pretext that we need four or six. As Payot wisely noted, “A little each day is enough, as long as a little is produced each day.”
The harm in certain things that are too distracting lies not so much in the time they steal from us as in the enervation they bring to the creative tension of the mind, and in the loss they cause to that quality of tone that nerve cells acquire when adapted to a particular subject.

Of course we don’t recommend the elimination of all distractions. However, those of the investigator should always be light and promote the association of new ideas. A stroll outside, contemplating works of art and photography, enjoying scenes such as monuments in different lands, the enchantment of music—and more than anything else the companionship of a person who understands us and carefully avoids all serious and reflective conversation—are the best ways for the laboratory worker to relax. Along these lines, it is wise to follow the advice of Buffon, who justified his abandon in conversation (which displeased many of those who admired the nobility, along with his elegant writing style) by noting: “These are my moments of rest.”

In summary, all great work is the fruit of patience and perseverance, combined with tenacious concentration on a subject over a period of months or even years. Many illustrious scholars have confirmed this when questioned about the secret of their creations. Newton stated that he arrived at the sovereign law of universal attraction only by constant thinking about the same problem. According to one of his sons, Darwin achieved such a high degree of concentration on the biological facts related to the principle of evolution that for many years he systematically deprived himself of all reading and contemplation unrelated to the goal of his thoughts. Buffon said unreservedly, “Genius is simply patience carried to the extreme.” To those who asked how he achieved fame he replied: “By spending forty years of my life bent over my writing desk.” As a final example, it is widely known that Mayer, the genius who discovered the principle of energy conservation and transformation, dedicated his entire life to this concept.
Thus, it is clear beyond doubt that great scientific undertakings require intellectual vigor, as well as severe discipline of the will and continuous subordination of all one’s mental powers to an object of study. Harm is caused unconsciously by the biographers of illustrious scholars when they attribute great scientific conquests to genius rather than to hard work and patience. What more could the weak will of the student or professor ask than to rationalize its laziness with the modest, and thus even more lamentable, admission of intellectual mediocrity! Not even biographers with the good sense of G.L. Figuier are immune from the regrettable trend of extolling beyond reason the mental gifts of famous investigators. Careful thought should make them realize how discouraging this can be to their readers. On the other hand, many autobiographies wherein the sage presents himself full-length to the reader provide an excellent moral tonic, showing weaknesses and passions, lapses and triumphs. After reading autobiographies that fill the soul with hope, you might well say: “Even I can be a painter!”

Scull on Foucault

Despite his fitting name, Andrew Scull is not in neuro. He is, however, a professor in the Department of Sociology at UCSD with psychiatry on the brain. Now aside from tickling my allusion fancy, Professor Scull has written several books, of which I can say I’ve at least thumbed through one: Madhouses, Mad Doctors and Madmen: Social History of Psychiatry in the Victorian Era. The thumbing was done for my History of Modern Medicine course which, in and of itself, was as inspiring as it was eye opening. That said, Professor Scull’s book is a favourite work of mine that comes to mind particularly as I near the end of my degree (along with Henri Ellenberger’s The Discovery of the Unconscious).

Needless to say I was happy to see Scull’s review of the newly translated edition of Michel Foucault’s History of Madness. More to the point, I was happy to see it was a scathing review. A quote:

Narrowness of this kind is not confined to footnotes. Foucault’s isolation from the world of facts and scholarship is evident throughout History of Madness. It is as though nearly a century of scholarly work had produced nothing of interest or value for Foucault’s project. What interested him, or shielded him, was selectively mined nineteenth-century sources of dubious provenance. Inevitably, this means that elaborate intellectual constructions are built on the shakiest of empirical foundations, and, not surprisingly, many turn out to be wrong.

Scull concludes his article, stating that

The back cover of History of Madness contains a series of hyperbolic hymns of praise to its virtues. Paul Rabinow calls the book “one of the major works of the twentieth century”; Ronnie Laing hails it as “intellectually rigorous”; and Nikolas Rose rejoices that “Now, at last, English-speaking readers can have access to the depth of scholarship that underpins Foucault’s analysis”. Indeed they can, and one hopes that they will read the text attentively and intelligently, and will learn some salutary lessons. One of those lessons might be amusing, if it had no effect on people’s lives: the ease with which history can be distorted, facts ignored, the claims of human reason disparaged and dismissed, by someone sufficiently cynical and shameless, and willing to trust in the ignorance and the credulity of his customers.

Oh yes, Foucault is finally fully translated into English. Me thinks it’s about time.

another excerpt from ‘a picture is worth 1000 words, but which 1000?’

it’s about time i started to put some excerpts from the neuroethics book edited by judy illes.  here’s another wonderful ditty from chapter 11:  a picture is worth 1000 words, but which 1000? 

italics are mine.

…from ch. 11 in Neuroethics…

What constitutes a ‘significantly greater’ activation than another, is in a way, in the eye of the beholder… lowering the threshold will create more regions that are statistically significant, whereas raising the threshold will reduce the number of significant regions. The choice of the threshold is largely determined by convention among researchers, rather than absolute standards. Reporting brain activation patterns is therefore primarily a statistical interpretation of a very complex dataset, and may be interpreted differently by different researchers. (Canli and Amin 2002)

YES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 

While group averages are vital for achieving acceptable signal-to-noise ratios, individual differences, from both anatomical and functional variability may become diluted and overshadowed (Beaulieu 2001; President’s Council on Bioethics 2004). When dealing with single-subject data, as is the case for presurgical planning, it is often desirable to minimize false-negative voxels in order to avoid erroneously excising potentially healthy tissue (M. P. Kirschen et al., under review). Outside the clinical setting, we can easily extend these considerations to any analytic objective set to pinpoint activation areas for function in individuals:

…the image of an activation pattern from a poorly designed study is visually indistinguishable from one based on an exemplary study. It takes a skilled practitioner to appreciate the difference. Therefore, one great danger lies in the abuse of neuroimaging data for presentations to untrained audiences such as courtroom juries. What can be easily forgotten when looking at these images is that they represent statistical inferences, rather than absolute truths. (Canli and Amin 2002)

YES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 

Lastly, the interpretability of fMRI activation maps is dependent on how the data are displayed. The colour-coded statistical maps are usually overlaid on high-resolution anatomical MR images to highlight the brain anatomy. There are several media for displaying these composite images. The most rigorous is to overlay the functional data onto single anatomical slices in any imaging plane. While this is the most comprehensive means of examining the data, it is often difficult to localize the activations to a particular region, given a particular scan plane, and researchers are limited in the number of slices they can include in a publication or lecture. Alternatively, the activation maps can be presented on a three-dimensional rendered brain. While this technique gives good visualization of prominent external brain structures, internal regions like the hippocampus or basal ganglia are not well characterized on these models. Researchers often use both of these techniques to examine data, but ultimately choose the one that best highlights the main results of the study for presentation.

Since basic research is usually done to infer characteristics bearing on populations, the extension to individual applications is challenged by a scarcity of normative data that can support, for example, conclusions of abnormal activation (Rosen and Gur 2002). There are risks that measures will vary between individuals or that the meaning of data compared with normal individuals will be difficult to establish. Abnormality and predictive validity could even be more problematic in the context of real-world behaviours, especially those that are potentially value laden or culturally determined (Illes et al., 2003).

Collingwood Revisited

I figured I’d repost this since Christmas is coming up. The link to amazon is at the bottom. ; )

‘An Essay on Metaphysics’ by Robin George Collingwood

IV

ON PRESUPPOSING

Whenever anybody states a thought in words, there are a great many more thoughts in his mind than are expressed in his statement. Among these there are some which stand in a peculiar relation to the thought he has stated: they are not merely its context, they are its presuppositions.

I write these words sitting on the deck of a ship. I lift my eyes and see a piece of string—a line I must call it at sea—stretched more or less horizontally above me. I find myself thinking ‘that is a clothes-line’, meaning that it was put there to hang washing on. When I decide that it was put there for that purpose I am presupposing that it was put there for some purpose. Only if that presupposition is made does the question arise, what purpose? If that presupposition were not made, if for example I had thought the line came here by accident, that question would not have arisen, and the situation in which I think ‘that is a clothes-line’ would not have occurred.

The priority affirmed in the word presupposition is logical priority. It is not a priority in time, whether that time belong to the history of the clothesline or to the history of my thoughts about it. When I say that its being for some purpose is a presupposition of its being for that purpose, that it first had a kind of general or indeterminate purposiveness, and that then, when it was rigged as a clothes-line, it exchanged this general or indeterminate purposiveness for a particular or determinate one by beginning to serve the purpose of hanging up washing to dry. I am not now asking whether anything like this really happened or not when the line was put up; I am only referring to when I used the word ‘presupposition’

Nor did I mean that my thoughts about the clothesline moved from ‘that line is meant for something’ to ‘that line is meant to hang washing on’. They might have moved in that way, and if I had been thinking about the line in an orderly or scientific manner I should have seen to it that they did move in that way; but as a matter of fact they did not. The thought ‘that is a clothes-line’ came plump into my mind, so far as I am aware, all at once and unheralded. Only by a kind of analysis, when I reflect upon it, do I come to see that this was a presupposition I was making, however little I was aware of it at the time.

Here lies the difference between the desultory and casual thinking of our unscientific consciousness and the orderly and systematic thinking we call science. In unscientific thinking our thoughts are coagulated into knots and tangles; we fish up a thought out of our minds like an anchor foul of its own cable, hanging upside-down and draped in seaweed with shellfish sticking to it, and dump the whole thing on deck quite pleased with ourselves for having got it up at all. Thinking scientifically means disentangling all this mess, and reducing a knot of thoughts in which everything sticks together anyhow to a system or series of thoughts in which thinking the thoughts is at the same time thinking the connexions between them.

Logicians have paid a great deal of attention to some kinds of connexion between thoughts, but to other kinds not so much. The theory of presupposition they have tended to neglect; and this is perhaps why the theory of metaphysics, which depends on it, has been allowed to remain in an unsatisfactory condition. I will try to state so much of this theory as seems necessary for my present purpose. For the sake of reference later on, I will sate it in a formal manner, in numbered propositions, with definitions of such terms as are used in sense they do not bear in ordinary English usage, or of terms whose meaning in ordinary usage depends on the propositions I am expounding. In expounding these propositions I shall not be trying to convince the reader of anything, but only to remind him of what he already knows perfectly well.

Prop. 1. Every statement that anybody ever makes is made in answer to a question.

When I speak of statements I do not mean only statements made out loud to somebody else; I include statements made by somebody to himself in the course of solitary thinking. Similarly when I speak of questions I do not mean only questions asked him by somebody else; I include questions asked him by himself.

The reader’s familiarity with the truth expressed in this proposition is proportional to his familiarity with the experience of thinking scientifically. In proportion as a man is thinking scientifically when he makes a statement, he knows that his statement is the answer to a question and knows what that question is. In proportion as he is thinking unscientifically he does not know these things. In our least scientific moments we hardly know what the thoughts we fish up out of our minds are answers to questions at all, let alone what questions these are. It is only by analyzing the thought which I expressed by saying ‘this is a clothes-line’ that I realize it to have been an answer to the question ‘what is that thing for?’ and come to see that I must have been asking myself that question although at the time I did not know I was asking it.

Note. A question is logically prior to its own answer. When thinking is scientifically ordered, this logical priority is accompanied by a temporal priority: one formulates the question first, and only when it is formulated begins trying to answer it. This is a special kind of temporal priority, in which the event or activity that is prior does not stop when that which is posterior begins. The act of asking the question begins and takes a definite shape as the asking of a determinate question before the act of answering it begins; but it continues for the whole duration of this latter. Unless the person who answered a question were still going on asking it while he formulated the answer, he would have ‘lost interest in the subject’, and the ‘answer’ would not have been an answer at all. It would have been a meaningless form of words. By being answered a question does not cease to be a question. It only ceases to be an unanswered question.

Def. 1. Let that which is stated (i.e. that which can be true or false) be called a proposition, and let stating it be called propounding it.

Note. This is an arbitrary use of the words. In English usage a question or supposition is, equally with a statement, said to be ‘propounded’, and the word ‘proposition’ is not exclusively used for that which is stated. I adopt it here, warning the reader that it is jargon, because it is customary among logicians.

Prop. 2. Every question involves a presupposition.

It may be doubted whether any question that was ever asked involved one presupposition and no more. Ordinarily a question involves large numbers of them. But a distinction should be made between what a question involves directly and what it involves indirectly. Directly or immediately, any given question involves one presupposition and only one, namely that form which it directly and immediately ‘arises’ (see Def. 2). This immediate presupposition, however, has in turn other presuppositions, which are thus indirectly presupposed by the original question.

Unless this immediate presupposition were made, the question to which it is logically immediately prior could not be logically asked. Verbally, no doubt, it might be asked. There is no verbal impossibility in the way of asking a man whom you suppose to be an indulgent husband whether he has stopped beating his wife. But there is a logical impossibility; for that question arises from the presupposition that he has been in the habit of beating her. If he is not supposed to have been in that habit, the question whether he has stopped ‘does not arise’.

Def. 2. To say that a question ‘does not arise’ is the ordinary English way of saying that it involves a presupposition which is not in fact being made.

A question that ‘does not arise’ is thus a nonsense question: not intrinsically nonsensical, but nonsensical in relation to its context, and specifically to its presuppositions. A person who asks another a question which ‘does not arise’ is talking nonsense and inviting the other to talk nonsense in the same vein.

As one can ask questions without knowing it, and a fortiori without knowing what questions one is asking, so one can make presuppositions without knowing it, and a fortiori without know what presuppositions one is making. When I ask ‘What is that thing for?’ I need not be aware that I am presupposing that it is ‘for’ something. It is only in proportion as I am thinking scientifically that I take trouble to make myself aware of this. For example, when I am trying to decipher a worn and damaged inscription I know very well that before I begin answering the question ‘What does that mark mean?’ I must first assure myself that the mark is not accidental but is part of the inscription; that is to say, I must first answer the question ‘Does it mean anything?’ An affirmative answer, i.e. the statement ‘That mark means something’, causes the question to arise, ‘What does it mean?’

Def. 3. The fact that something causes a certain question to arise I call the ‘logical efficacy’ of that thing.

The question ‘What does that mark mean?’ would equally have been caused to arise if I had not stated but only ‘assumed’ or ‘supposed for the sake of argument’ that it means something; and this is what, like any other epigraphist, I do when I find myself unable to give a definite answer to the question whether a certain mark is part of the inscription or not. The logical efficacy of the supposition that the mark means something is identical with the logical efficacy of the proposition that it means something.

Def. 4. To assume is to suppose by an act of free choice.

A person who ‘makes an assumption’ is making a supposition about which he is aware that he might, if he chose, make not that but another. All assumptions are suppositions, but all suppositions are not assumptions; for some are made altogether unawares, and others, thought the persons who make them may be conscious of making them, are made without any consciousness of the possibility, if it is a possibility, that others might have been made instead. When correctly used, the word ‘assumption’ is always used with this implication of free choice, as when it is said ‘let us assume x = 10’. Sometimes it is in correctly used of malice prepense, by way of an insult; as when a man says to another with whom he is arguing, ‘you are assuming that no one will work except for payment’, where the point is that no one but a fool would make that assumption, though it is a supposition that might easily be made unawares. Similarly a man who wishes to be insulting may ask ‘What do you mean by treading on my toe?’ knowing perfectly well that the treader meant nothing by it, because he did not do it on purpose.

Prop. 3. The logical efficacy of a supposition does not depend upon the truth of what is supposed, or even on its being thought true, but only on its being supposed.

The point has already been made clear in discussing the previous proposition. It is a matter of common knowledge in the conduct of scientific thinking; where it is possible and often profitable to argue from suppositions which we know to be false, or which we believe to be false, or concerning which we have neither knowledge nor belief as to whether they are false or true. These doubts or negations in no way affect the validity of the argument.

The point is no less familiar in the conduct of practical affairs than it is in the conduct of scientific thinking. A man (or at any rate an intelligent man) does not regard himself as insulted if some one who has paid him a sum of money asks him for a receipt, or if the family of a lady whom he is about to marry proposes that a marriage settlement should be drawn up. He knows that the request or proposal is based on the assumption that he is capable, or will one day become capable, of acting dishonourably; but though he knows people assume this he does not necessarily think they believe it. He finds no difficulty in his distinguishing between their supposing him a rascal and their believing him one, and he does not regard the former as evidence of the latter.

Prop. 4. A presupposition is either relative or absolute.

In this context the word ‘presupposition’ refers not to the act of presupposing but to that which is presupposed.

Def. 5. By a relative presupposition I mean one which stands relatively to one question as its presupposition and relatively to another question as its answer.

Thus, if I do a piece of surveying in the course of which I take some hundreds of measurements with my old 66-foot tape, every time I ask any question in the form ‘What is the distance between these two points?’ I presuppose that the answer as given by a reading on my tape will be the right answer: that is, I presuppose that my tape is within a certain percentage of the length which it professes to be. But this is only a relative presupposition. A tape by a reputable maker is not likely to have been made grossly inaccurate in the first instance; but it is quite likely to have stretched during years of service in all weathers; and a sensible man will check it from time to time against something not liable to that accident, for example a surveyor’s chain. The accuracy of the tape, which while I am using it is a presupposition of the questions I ask, is one of the two possible answers, the affirmative answer, to the question I ask while I am thus checking it.

A man may use a measuring-tape without its ever occurring to him that the question of its accuracy might be raised. In that case his assumption of its accuracy remains unquestioned, and one might suppose that this fact removed it from the sphere of relative presuppositions as above defined. But this would be a mistake. That a certain conclusion follows from certain premises is not disproved by the fact that some one who states the premises fails to see that the conclusion follows. Similarly, that certain presuppositions are questionable is not disproved by the fact that some one who makes them fails to see that they are questionable. The business of logical inquiries, like that on which we are now engaged, is to study high-grade or scientific thinking: their conclusions are not impaired by the fact that low-grade or unscientific thinking also exists.

To question a presupposition is to demand that is should be ‘verified’; that is, to demand that a question should be asked to which the affirmative answer would be that presupposition itself, now in the form of a proposition. To verify the presupposition that my measuring-tape is accurate is to ask a question admitting of the alternative answers ‘the tape is accurate’, ‘the tape is not accurate’. Hence to speak of verifying a presupposition involves supposing that it is a relative presupposition.

Def. 6. An absolute presupposition is one which stands, relatively to all questions to which it is related, as a presupposition, never as an answer.

Thus if you were talking to a pathologist about a certain disease and asked him ‘What is the cause of the event E which you say sometimes happens in this disease?’ he will reply ‘The cause of E is C’; and if he were in a communicative mood he might go on to say ‘That was established by So-and-so, in a piece of research that is now regarded as classical.’ You might go on to ask: ‘I suppose before So-and-so fount out what the cause of E was, he was quite sure it had a cause?’ The answer would be ‘Quite sure, of course.’ If you now say ‘Why?’ he will probably answer ‘Because everything that happens has a cause.’ If you are importunate enough to ask ‘But how do you know that everything that happens has a cause?’ he will probably blow up right in your face, because you have put your finger on one of his absolute presuppositions, and people are apt to be ticklish in their absolute presuppositions. But if he keeps his temper and gives you a civil and candid answer, it will be to the following effect. ‘That is a thing we take for granted in my job. We don’t question it. We don’t try to verify it. It isn’t a thing anybody has discovered, like microbes or the circulation of the blood. It is a thing we just take for granted.’

He is telling you that it is an absolute presupposition of the science he pursues; and I have made him a pathologist because this absolute presupposition about all events having causes, which a hundred years ago was made in every branch of natural science, has now ceased to be made in some branches, but medicine is one of those in which it is still made.

Absolute presuppositions are not verifiable. This does not mean that we should like to verify them but are not able to; it means that the idea of verification is an idea which does not apply to them, because, as I have already said, to speak of verifying a presupposition involves supposing that it is a relative presupposition. If anybody says ‘Then they can’t be of much use in science’, the answer is that their use in science is their logical efficacy, and that the logical efficacy of a supposition does not depend on its being verifiable, because it does not depend on its being true: it depends only its being supposed (prop. 3).

Prop. 5. Absolute presuppositions are not propositions.

This is because they are never answers to questions (def. 6); whereas a proposition (def. 1) is that which is stated, and whatever is stated (prop. 1) is stated in answer to a question. The point I am trying to make clear goes beyond what I have just been saying, viz. that the logical efficacy of an absolute presupposition is independent of its being true: it is that the distinction between truth and falsehood does not apply to absolute presuppositions at all, that distinction being (see def. 1) peculiar to propositions.

Putting the same point differently: absolute presuppositions are never (see def. 1) propounded. I do not mean that they sometimes go unpropounded, like the so-called ‘propositions’ of the fashionable modern logic, which are called propositions even when nobody in fact propounds them, and would on that account be more accurately called ‘proponibles’; I mean that they are never propounded at all. To be propounded is not their business; their business is to be presupposed. The scientist’s business is not to propound them but only to presuppose them. The metaphysician’s business, as we shall see, is not to propound them but to propound the proposition that this or that one of them is presupposed.

Hence any question involving the presupposition that an absolute presupposition is a proposition, such as the questions ‘Is it true?’ ‘What evidence is there for it?’ “How can it be demonstrated?’ ‘What right have we to presuppose it if it can’t?’, is a nonsense question.

Hence, too, it is nonsense to say, as some modern logicians do say, that supposing is one of various ‘attitudes’ which we can take up towards a proposition, where a proposition means something which can be either true or false. This is merely a device for imposing on unwary readers the dogma, of which more will be said hereafter, that all presuppositions are relative, or that there are no absolute presuppositions.

More here and here.

“Minus times minus equals plus / The reason for this we need not discuss.”

My physics professor’s maxim was ‘ignore symmetry at your peril’.

A little mystery here.

And the book over here.

Sneak a peek at Minksy!

Marvin Minsky’s new book, ‘The Emotion Machine’, is available in draft format from his homepage. 

Sections 1-9:  1 2 3 4 5 6 7 8 9

From Publishers Weekly
Twenty years after The Society of Mind, where he introduced the concept that “minds are what brains do,” Minsky probes deeper into the question of natural intelligence. Don’t look for simple explanations: he believes “we need to find more complicated ways to explain our most familiar mental events”; we need to break our thought processes down into the most precise steps possible. In fact, in order to truly understand the human mind, Minsky suggests, we’ll probably need to reverse-engineer a machine that can replicate those functions so we can study it. Thus, he rejects the idea of consciousness as a unitary “Self” in favor of “a decentralized cloud” of more than 20 distinct mental processes. In this view, emotional states like love and shame are not the opposite of rational cogitation; both, Minsky says, are ways of thinking. This is not a book to be read casually; Minsky builds his argument with constant reference to earlier and later sections, imagining objections from a variety of philosophical positions and refuting them. A steady stream of diagrams helps clarify matters, but readers will be forced to dig for the “aha!” moments: they’re worth the effort. 100 b&w illus. (Nov. 7)
Copyright © Reed Business Information, a division of Reed Elsevier Inc. All rights reserved.

Excerpt from C. S. Lewis’ ‘The Screwtape Letters’

 

My Dear Wormwood,

 

I note what you say about guiding your patient’s reading and taking care that he sees a good deal of his materialist friend.  But are you not being a trifle naïf?  It sounds as if you supposed that argument was the way to keep him out of the Enemy’s clutches.  That might have been so if he had lived a few centuries earlier.  At that time the humans still knew pretty well when a thing was proved and when it was not; and if it was proved they really believed it.  They still connected thinking with doing and were prepared to alter their way of life as the result of a chain of reasoning.  But what with the weekly press and other such weapons we have largely altered that.  Your man has been accustomed, ever since he was a boy, to have a dozen incompatible philosophies dancing about together inside his head.  He doesn’t think of doctrines as primarily ‘true’ or ‘false’, but as ‘academic’ or ‘practical’, ‘outworn’ or ‘contemporary’, ‘conventional’ or ‘ruthless’.  Jargon, not argument is your best ally in keeping him from the Church.  Don’t waste time trying to make him think that materialism is true!  Make him think it is strong, or stark, or courageous—that it is the philosophy of the future.  That’s the sort of thing he cares about.

 

The trouble about argument is that it moves the whole struggle onto the Enemy’s own ground.  He can argue too; whereas in really practical propaganda of the kind I am suggesting He has been shown for centuries to be greatly the inferior of Our Father Below.  By the very act of arguing, you awake the patient’s reason; and once it is awake, who can foresee the result?  Even if a particular train of thought can be twisted so as to end in our favour, you will find that you have been strengthening in your patient the fatal habit of attending to universal issues and withdrawing his attention from the stream of immediate sense experiences.  Your business is to fix his attention on the stream.  Teach him to call it ‘real life’ and don’t let him ask what he means by ‘real’.

Remember, he is not, like you, a pure spirit.  Never having been a human (Oh that abominable advantage of the Enemy’s!) you don’t realize how enslaved they are to the pressure of the ordinary.  I once had a patient, a sound atheist, who used to read in the British Museum.  One day, as he sat reading, I saw a train of thought in his mind beginning to go the wrong way.  The Enemy, of course, was at his elbow in a moment.  Before I knew were I was I saw my twenty years’ work beginning to totter.  If I had lost my head and begun to attempt a defense by argument I should have been undone.  But I was not such a fool.  I struck instantly at the part of the man which I had best under my control and suggested that it was just about time he had some lunch.  The Enemy presumably made the counter-suggestion (you know how one can never quite overhear what He says to them?) that this was more important than lunch.  At least I think that must have been His line for when I said ‘Quite.  In fact much too important to tackle at the end of a morning’, the patient brightened up considerably; and by the time I had added ‘Much better come back after lunch and go into it with a fresh mind’, he was already half way to the door.  Once he was in the street the battle was won.  I showed him a newsboy shouting the midday paper, and a No. 73 bus going past, and before he reached the bottom of the steps I had got into him an unalterable conviction that, whatever odd ideas might come into a man’s head when he was shut up alone with his books, a healthy dose of ‘real life’ (by which he meant the bus and the newsboy) was enough to show him that all ‘that sort of thing’ just couldn’t be true.  He knew he’d had a narrow escape and in later years was fond of talking about ‘that inarticulate sense for actuality which is our ultimate safeguard against the aberrations of mere logic’.  He is now safe in Our Father’s house.

You begin to see the point?  Thanks to processes which we set at work in them centuries ago, they find it all but impossible to believe in the unfamiliar while the familiar is before their eyes.  Keep pressing home on him the ordinariness of things.  Above all, do not attempt to use science (I mean, the real sciences) as a defense against Christianity. They will positively encourage him to think about realities he can’t touch and see.  There have been sad cases among the modern physicists.  If he must dabble in science, keep him on economics and sociology; don’t let him get away from that invaluable ‘real life’.  But the best of all is to let him read no science but to give him a grand general idea that he knows it all and that everything he happens to have picked up in casual talk and reading is ‘the results of modern investigation’.  Do remember you are there to fuddle him.  From the way some of you young fiends talk, anyone would suppose it was our job to teach!

           

                        Your affectionate uncle

                                                            Screwtape

Boooooooooks!

The past weekend has been overly draining and excessively stressful.  Thank goodness things have lightened up at job no. 2 of 3 and I have time to surf.  I was  most excited to discover Google Books today and my stress levels have gone down appreciably since I’ve started to read William James’ Principles of Psychology. 

Quite shocking to think where this could lead.  I appreciate catching wind of the latest neuro research online as much as the next nerd, but to think that books, real books, are being scanned!  And searchable!  I can only shudder at the hippy googling ‘brain’ and making loose conjectures between Penfield, James, and hasheesh.  Or the somber, pretentious post-modernist writing a treatise on the hegemony of 19th century frog experiments and the resultant marginalization of the toad/other by simply clicking ’search’.  But, the future, the ability to compare translations, to thoughtfully rediscover past conjectures, this is quite exciting.  Makes one wonder what is happening at Google behind the scenes.  Murmurings from the CBC and the like already point to difficulties:  lawsuits on copyright, decisions made dictating which books will be scanned, access to books in different countries.  It’s brave new world out there.  Cowboy up.

Without further ado, The Bookshelf.  Gems located inside.

Another excerpt from ‘Conjectures and Refutations’

On why Newton’s theory did not derive from observation.

I was back home this afternoon. I let this churn in my brain for a while, then passed on the churning to my sister. After a lot of pacing we figured out how difficult this is when you don’t recognize what’s being said and how obvious it seems after a lot of pacing.

(Chapter 8)

// My third point—the contention that it is logically impossible to derive Newton’s theory from observations—follows immediately from Hume’s critique of the validity of inductive inferences, was pointed out by Kant. Hume’s decisive point may be put as follows:

Take a class consisting of any number of true observation-statements and designate it by the letter K. The statements in the class K will describe actual observations, i.e. past observations: thus we designate by the letter K any class whatsoever of true statements about observations actually made in the past. Since we have assumed that K consists only of true statements, all statements in the class K must also be consistent statements, and, furthermore, all statements belonging to the class K must be compatible with one another. Now take a further observation-statement which we shall designate by the letter B. We assume that B describes some future, logically possible, observation; for example, that B tells us that there will be an eclipse of the sun tomorrow. Since eclipses of the sun have already been observed, we can be certain that a statement B, asserting that there will be an eclipse of the sun tomorrow, is a statement which, on purely logical grounds, is possible; that is to say, our B is self-consistent. Now Hume shows the following: if B is a self-consistent observation-statement about a possible future event, and K any class of true observation-statements about past events, then B can always be conjoined with K without contradiction; or, in other words, if we add a statement B about a possible future event to statements in K we can never arrive at a logical contradiction. Hume’s finding can also be formulated as follows: no logically possible future observation can ever contradict the class of past observations.

Let us now add to Hume’s simple finding a theorem of pure logic, namely: whenever a statement B can be conjoined without contradiction to a class of statements K, then it can also be conjoined without contradiction to any class of statements that consists of statements of K together with any statement that can be derived from K.

And so we have proved our point: if Newton’s theory could be derived from a class K of true observation-statements, then no future observation B could possibly contradict Newton’s theory and the observations K.

Yet it is known, on the other hand, that from Newton’s theory and past observations we can logically derive a statement that tells us whether or not there will be an eclipse of the sun tomorrow. Now if this derived statement tells us that tomorrow there will be no eclipse of the sun, then our B is clearly incompatible with Newton’s theory and the class K. From this and our previous results it follows logically that it is impossible to assume that Newton’s theory can be derived from observations.