Complex systems that have artificially suppressed volatility tend to become extremely fragile

Nassim Nicholas Taleb is a brilliant thinker, philosopher and writer. I have read and enjoyed Fooled by Randomness as well as Black Swan and am looking forward to his most recent, Antifragile (reviewed in The Economist here).

Taleb had an article in Foreign Affairs in 2011 which hit on some of his main arguments (as applied to international relations) - The Black Swan of Cairo. Black Swan is Taleb's term for an unpredicted (and essentially unpredictable) event that disrupts the status quo.

Complex systems that have artificially suppressed volatility tend to become extremely fragile, while at the same time exhibiting no visible risks. In fact, they tend to be too calm and exhibit minimal variability as silent risks accumulate beneath the surface. Although the stated intention of political leaders and economic policymakers is to stabilize the system by inhibiting fluctuations, the result tends to be the opposite. These artificially constrained systems become prone to “Black Swans”—that is, they become extremely vulnerable to large-scale events that lie far from the statistical norm and were largely unpredictable to a given set of observers.

Such environments eventually experience massive blowups, catching everyone off-guard and undoing years of stability or, in some cases, ending up far worse than they were in their initial volatile state. Indeed, the longer it takes for the blowup to occur, the worse the resulting harm in both economic and political systems.

[snip]

Humans simultaneously inhabit two systems: the linear and the complex. The linear domain is characterized by its predictability and the low degree of interaction among its components, which allows the use of mathematical methods that make forecasts reliable. In complex systems, there is an absence of visible causal links between the elements, masking a high degree of interdependence and extremely low predictability. Nonlinear elements are also present, such as those commonly known, and generally misunderstood, as “tipping points.” Imagine someone who keeps adding sand to a sand pile without any visible consequence, until suddenly the entire pile crumbles. It would be foolish to blame the collapse on the last grain of sand rather than the structure of the pile, but that is what people do consistently, and that is the policy error.

[snip]

Engineering, architecture, astronomy, most of physics, and much of common science are linear domains. The complex domain is the realm of the social world, epidemics, and economics. Crucially, the linear domain delivers mild variations without large shocks, whereas the complex domain delivers massive jumps and gaps. Complex systems are misunderstood, mostly because humans’ sophistication, obtained over the history of human knowledge in the linear domain, does not transfer properly to the complex domain. Humans can predict a solar eclipse and the trajectory of a space vessel, but not the stock market or Egyptian political events. All man-made complex systems have commonalities and even universalities. Sadly, deceptive calm (followed by Black Swan surprises) seems to be one of those properties.

Taleb also mentions but does not elaborate on, the important issue of "the illusion of local causal chains—that is, confusing catalysts for causes and assuming that one can know which catalyst will produce which effect." There is a tendency to see the last event as the "cause" of something when in fact it is sometimes simply the catalyst to a systemic readjustment, i.e. the straw that broke the camel's back. It wasn't the straw per se, but the cumulative weight that preceded it.

There are echoes of Stephen Jay Gould and Niles Edlredge's Punctuated Equilibrium in which they argued that evolution is not a smooth continual process but rather a process characterized by fits and starts or a system of punctuated equilibrium.

Taleb is arguing that our efforts to ensure near term tactical stability are often at odds with desirable system evolution over the long run. It is a classic trade-off decision. He has observed many times that the good tactical intentions often end up unintentionally leading to catastrophic strategic outcomes. An example would be that of forest fire management. Nobody wants forest fires and for decades the strategy was simple fire suppression, keep fires from happening and put them out as fast as possible when they do happen.

In reducing near term fires, regrettably, forests have accumulated much greater fuel loads than they would otherwise under natural conditions where lightning strike fires periodically clear dead brush. The result has been increasingly frequent, vast and intense wildfires beyond control. A strategy for achieving near term stability (reduced wildfires) has ended up worsening the situation in the long run.

When making a strategic decision, it is important to consider the historical context. Has the existing system evolved over time and therefore has some base level of stability, or has it existed in an unnatural state of artificial stability with all variance suppressed? If it is the latter, then any actions undertaken related to a new change may have unanticipated consequences not necessarily having anything to do with the intended plan of action but simply as a consequence of cumulative avoided evolution.

Specialization is for insects

Time Enough For Love by Robert A. Heinlein, page 248

A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.

Advocates of luck as an explanation are enemies of freedom

From We Owe the Beatles to Luck by Cass R. Sunstein.

You might think that the Beatles, probably the most successful popular musicians in the last 50 years, were bound to succeed. But an astonishing new book, "Tune In," by Mark Lewisohn, suggests otherwise. Without explicitly saying so, Lewisohn’s narrative raises the possibility that without breaks, coincidences and a lot of luck, none of us would have ever heard of the Beatles.

The author recounts a long string of barriers and reverses preventing the Beatles from gaining traction. Until they did.

These kind of articles drive me crazy. There is a whole world view eager to establish that successful people are simply lucky people. That success is purely a matter of being in the right place at the right time. The paradoxical thing is that these people, and Sunstein is an example, are usually quite successful themselves. It is hard to believe that they believe their own positive outcomes are purely based on luck and that they had no material contribution to the outcome.

Malcolm Gladwell made much the same argument in Outliers.

People that believe all outcomes are essentially a matter of luck tend also to believe that that contingency therefore justifies collective action to rectify mere luck. If you did not earn your success, the argument goes, you are not entitled to it. If all outcomes are simply random luck, then all success can be justifiably appropriated to rectify the bad luck of others.

Human processes are non-linear and complex with unexpected tipping points, hidden feedback loops, extreme sensitivity to initial conditions and other characteristics which make it very difficult to precisely and accurately forecast a given outcome for specified inputs. Things like architecture, engineering, manufacturing, Newtonian physics are all nice, predictable, and incremental in nature. Do X and Y occurs. The Sunsteins of the world take this hoary way of thinking and apply it with great confidence to the human condition to great disappointment of all parties.

Looking at the experience of the Beatles, it is undeniable that there were a lot of random events and contingent circumstances preceding their eventual success. The reality is that any endeavor is prone to failure; failure is pretty much the norm. It is the taking of chances and the perseverance and adaption to new circumstances which distinguish the eventual success from the otherwise to be expected failure. Were the Beatles lucky? Sure. But only because they continued to take the risks and persevered in the face of failure, time and again, until ultimately they accomplished what they did.

Seneca, On Benefits, vii. 1

"The best wrestler," he would say, "is not he who has learned thoroughly all the tricks and twists of the art, which are seldom met with in actual wrestling, but he who has well and carefully trained himself in one or two of them, and watches keenly for an opportunity of practising them."

Often summarized as Luck is what happens when preparation meets opportunity.

Luck is not an explanation, it is a given. We all exist in an environment of fluctuating randomness and desirable outcomes are only achieved through the capacity to manage the consequences of that fluctuating randomness. Some do this well, others not.

Never will man penetrate deeper into error than when he is continuing on a road which has led him to great success.

The Counter-Revolution of Science: Studies on the Abuse of Reason by F.A. Hayek, page 105.

Never will man penetrate deeper into error than when he is continuing on a road which has led him to great success.

This is a dual truism arising from faulty forecasting and overconfidence. Specifically, a run of success tends to encourage a belief that we have conquered failure and setbacks and we forecast into the future the current trend line. Thus are all bubbles created whether internet stocks or real estate. Forecasted catastrophe's likewise. All my life we have been at peak oil and then some new technology comes along opening up previously inaccessible reserves. Despite all our knowledge and experience, there are structural quirks that encourage straight line forecasting to the detriment of accurate forecasting.

The second truism arises from knowledge confidence. We are successful. We explain that success based on some set of actions or circumstances; usually some set of actions we took given some particular circumstances. Typically, our narrative explanation for success emphasizes our own contribution and minimizes circumstance and luck (Nassim Nicholas Taleb cover's this ground in Fooled by Randomness). Our explanation may be more or less accurate but the longer the success continues, the more confident we are in our explanation regardless of the truth. Our search for accurate explanations slackens with out confidence.

Your example will educate him; your conversation with your friends; the business he sees you transact; the likings and dislikings you express; these will educate him

From On Education by Anna Barbauld, 1773. Proving that great antiquity does not preclude great insight. In fact, one could argue that Barbauld's insight, that education is the cumulative aggregation of all experiences seems to have disappeared from the minds of policy makers today. The time spent in school as Barbauld observes, is but a very small part of that education and yet all our efforts to equalize the benefits of opportunity between neo-natal citizens is largely constrained to formal education. It is the classic story of the drunk looking for his lost keys under the street lamp, not because that is where he thinks he lost them, but because that is where the light is best.

Paragraphing and emphasis added.

The other day I paid a visit to a gentleman with whom, though greatly my superior in fortune, I have long been in habits of an easy intimacy. He rose in the world by honourable industry; and married, rather late in life, a lady to whom he had been long attached, and in whom centered the wealth of several expiring families. Their earnest wish for children was not immediately gratified. At length they were made happy by a son, who, from the moment he was born, engrossed all their care and attention. -- My friend received me in his library, where I found him busied in turning over books of education, of which he had collected all that were worthy notice, from Xenophon to Locke, and from Locke to Catherine Macauley. As he knows I have been engaged in the business of instruction, he did me the honour to consult me on the subject of his researches, hoping, he said, that, out of all the systems before him, we should be able to form a plan equally complete and comprehensive; it being the determination of both himself and his lady to choose the best that could be had, and to spare neither pains nor expense in making their child all that was great and good. I gave him my thoughts with the utmost freedom, and after I returned home, threw upon paper the observations which had occurred to me.

The first thing to be considered, with respect to education, is the object of it. This appears to me to have been generally misunderstood. Education, in its largest sense, is a thing of great scope and extent. It includes the whole process by which a human being is formed to be what he is, in habits, principles, and cultivation of every kind. But of this, a very small part is in the power even of the parent himself; a smaller still can be directed by purchased tuition of any kind. You engage for your child masters and tutors at large salaries; and you do well, for they are competent to instruct him: they will give him the means, at least, of acquiring science and accomplishments; but in the business of education, properly so called, they can do little for you. Do you ask, then, what will educate your son? Your example will educate him; your conversation with your friends; the business he sees you transact; the likings and dislikings you express; these will educate him; -- the society you live in will educate him; your domestics will educate him; above all, your rank and situation in life, your house, your table, your pleasure-grounds, your hounds and your stables will educate him. It is not in your power to withdraw him from the continual influence of these things, except you were to withdraw yourself from them also.

You speak of beginning the education of your son. The moment he was able to form an idea his education was already begun; the education of circumstances -- insensible education -- which, like insensible perspiration, is of more constant and powerful effect, and of infinitely more consequence to the habit, than that which is direct and apparent. This education goes on at every instant of time; it goes on like time; you can neither stop it nor turn its course. What these have a tendency to make your child, that he will be. Maxims and documents are good precisely till they are tried, and no longer; they will teach him to talk, and nothing more. The circumstances in which your son is placed will be even more prevalent than your example; and you have no right to expect him to become what you yourself are, but by the same means. You, that have toiled during youth, to set your son upon higher ground, and to enable him to begin where you left off, do not expect that son to be what you were, -- diligent, modest, active, simple in his tastes, fertile in resources. You have put him under quite a different master. Poverty educated you; wealth will educate him. You cannot suppose the result will be the same. You must not even expect that he will be what you now are; for though relaxed perhaps from the severity of your frugal habits, you still derive advantage from having formed them; and, in your heart, you like plain dinners, and early hours, and old friends, whenever your fortune will permit you to enjoy them.

But it will not be so with your son: his tastes will be formed by your present situation, and in no degree by your former one. But I take great care, you will say, to counteract these tendencies, and to bring him up in hardy and simple manners; I know their value, and am resolved that he shall acquire no other. Yes, you make him hardy; that is to say, you take a country-house in a good air, and make him run, well clothed and carefully attended, for, it may be, an hour in a clear frosty winter's day upon your graveled terrace; or perhaps you take the puny shivering infant from his warm bed, and dip him in an icy cold bath, -- and you think you have done great matters. And so you have; you have done all you can. But you were suffered to run abroad half the day on a bleak heath, in weather fit and unfit, wading barefoot through dirty ponds, sometimes losing your way benighted, scrambling over hedges, climbing trees, in perils every hour both of life and limb. Your life was of very little consequence to any one; even your parents, encumbered with a numerous family, had little time to indulge the softnesses of affection, or the solicitude of anxiety; and to every one else it was of no consequence at all. It is not possible for you, it would not even be right for you, in your present situation, to pay no more attention to your child than was paid to you. In these mimic experiments of education, there is always something which distinguishes them from reality; some weak part left unfortified, for the arrows of misfortune to find their way into.

I think that issue highlighted by Barbauld, that the circumstances that shaped your own personal KESVB (Knowledge, Experience, Skills, Values, Behavior) and enabled your own personal achievement, cannot be replicated for your child. Your child is, paradoxically, precluded from the opportunity that fostered the success generating KESVB of the parent. With luck their own new KESVB is pertinent to the new circumstances of the child but it is the greatest challenge of every parent who has been productively successful, to create an environment where the origin KESVB can be replicated.

I suspect this is the origin to the dynamic reflected in the old adage (and universal, variants show up in many different cultures) "shirt sleeves to shirt sleeves in three generations." Old productive cultures and religions are probably the best supplements to personal experience - i.e. the child of privilege can't learn from experience, therefore there has to be some other motivating factor and passion which compensates for the indolence of privilege. Unfortunately, experience is that the novelty of ideologies too often takes the place of proven religion and culture. That explains why so many revolutionaries are from the privileged class rather than from the down trodden as logic would dictate.

But we are all Seekers

The Seekers by Daniel J. Boorstin.

Caught between two eternities - the vanished past and the unknown future - we never cease to seek our bearings and our sense of direction. We inherit our legacy of the sciences and the arts - works of the great Discoverers and Creators, the Columbuses and Leonardos and Shakespeares - recounted in my two earlier volumes. We glory in their discoveries and creations. But we are all Seekers. We all want to know why. Man is the asking animal. And while the finding, the belief that we have found the Answer, can separate us and make us forget our humanity, it is the seeking that continues to bring us together, that makes us and keeps us human.

People are people no matter our measures and averages.

I have always been bothered by the overreliance of some on self-identity. We get hung up on terms and definitions and froth around about the meaning of trends we don't understand. As a minor example, were my niece and nephews to immigrate to the US from Europe, the census would regard the white population as having been increased. If, on the other hand, they immigrated to Argentina for a couple of years and then came to the US, they would be regarded as Hispanic (because of their paternal heritage) and the Hispanic numbers would increase. And from my perspective, I would have a niece and a couple of nephews closer to home. Our definitions and terminology sometimes get in the way of understanding the important things.

I first became alerted to the fluidity of definitions back in the seventies. After one of the OPEC embargoes, the price of oil went through the roof. In the following census, a couple of Native American tribes showed an increase in population of more than a hundred percent, an impossible fecundity. How were these issues related? Price of oil goes up. Several Native American tribes had reservation land that included oil production. The proceeds of that oil production was distributed to enrolled members. When the value of the oil went up, people who did not otherwise identify as Native American but did in fact have that heritage, enrolled as was their prerogative in order to benefit from the windfall. And thus the census numbers went up with no change in the underlying reality of people.

This is brought to mind by a recent post, Pew Study: 27% of Jewish Children Live in Orthodox Homes by David Bernstein. I have read elsewhere of this study and there apparently was an awful lot of interesting discussion regarding definitions (Orthodox, Conservative, Reformed, etc.). Notice the last sentence, though, in this post:

But with being Jewish no longer a substantial disadvantage in American life, and intermarriage unlikely in non-Orthodox circles to lead to serious family disruption, the new Pew study finds hundreds of thousands of children of intermarriage identify as Jews of no religion (and about as many as Jews by religion), hundreds of thousands of others who were raised Jewish but don’t consider themselves such but who acknowledge their Jewish ancestry, and, a bit weirdly, hundreds of thousands of additional individuals who have no Jewish ancestry and who have never converted but for whatever reason consider themselves to be Jewish.

I love that; "a bit weirdly, hundreds of thousands of additional individuals who have no Jewish ancestry and who have never converted but for whatever reason consider themselves to be Jewish." Among other things it is a very loud call to be cautious about survey data. It is not always telling us what we thinking it is saying, no matter how rigorous and effectively it might have been administered. Several hundred thousand people claiming a heritage that in no other context would people recognize, is just plain fascinating. People are people no matter our measures and averages.

A pledge by all parties not to learn anything while doing the actual work

Two articles that are interesting to read as a pair. Both Clay Shirky and Peter Berkowitz are almost always interesting and insightful The first article, by Shirky is a rumination on the Healthcare.gov failure, not as a failed information systems project per se (though it is a fairly spectacular example of that), but rather as an epistemological failure which I believe is really at the core of the issue. And the epistemological model is in part a failure of culture.

Very early in Obama's first term, there was a desire on the part of the Administration to close Guantanamo and bring the terrorists held there to the US for civil trial. There was quite a kerfuffle when it came time to consider a civilian trial for Khalid Sheikh Mohammad. In the hearings to review this plan, the Attorney General Eric Holder had the following profoundly revealing exchange with Senator Herbert Kohl, Democrat, Wisconsin.

Kohl: Mr. Holder, last week you announced that the department will bring to Guantanamo [sic in transcript] detainees accused of planning the 9/11 attacks to trial in federal court in New York, as we've talked about this morning. On Friday you said that you'd not have authorized prosecution if you were not confident that the outcome would be successful. However, many critics have offered their own predictions about how such a trial might well play out.

One concern we have heard from critics of your decision is that the defendants could get off on legal technicalities, in which case these terrorists would walk free. Does this scenario have any merit? If not, why? And in the worst case scenario that the trial does not result in a conviction, what would be your next steps?

Holder: Many of those who have criticized the decision--and not all--but many of those who have criticized the decision have done so, I think, from a position of ignorance. They have not had access to the materials that I have had access to.

They've not had a chance to look at the facts, look at the applicable laws and make the determination as to what our chances of success are. I would not have put these cases in Article III courts if I did not think our chances of success were not good--in fact, if I didn't think our chances of success were enhanced by bringing the cases there. My expectation is that these capable prosecutors from the Justice Department will be successful in the prosecution of these cases.

Kohl: But taking into account that you never know what happens when you walk into a court of law, in the event that for whatever reason they do not get convicted, what would be your next step? I'm sure you must have talked about it.

Holder: What I told the prosecutors and what I will tell you and what I spoke to them about is that failure is not an option. Failure is not an option. This--these are cases that have to be won. I don't expect that we will have a contrary result.

I found this profoundly shocking from two perspectives. Either what the AG said was true and that failure would not be countenanced, in which case this was simply a show trial. He wasn't arguing that failure was unlikely, he was arguing that it couldn't happen at all.

Alternatively, the most senior lawyer in the land truly believed that there was simply no way that an unbiased and fair jury trial could render anything other than a guilty verdict. A belief that could not possibly be grounded in experience or reality.

The distress was the realization that our AG was either corrupt (rigged trial) or stupid (mistaking desire for reality). It seemed that there were few alternative interpretations. But perhaps it was simply a flawed epistemological model founded on a faulty culture. Read Shirky's whole post to see the parallels with the Healthcare.gov failure.

From Healthcare.gov and the Gulf Between Planning and Reality by Clay Shirky

The idea that “failure is not an option” is a fantasy version of how non-engineers should motivate engineers. That sentiment was invented by a screenwriter, riffing on an after-the-fact observation about Apollo 13; no one said it at the time. (If you ever say it, wash your mouth out with soap. If anyone ever says it to you, run.) Even NASA’s vaunted moonshot, so often referred to as the best of government innovation, tested with dozens of unmanned missions first, several of which failed outright.

Failure is always an option. Engineers work as hard as they do because they understand the risk of failure. And for anything it might have meant in its screenplay version, here that sentiment means the opposite; the unnamed executives were saying “Addressing the possibility of failure is not an option.”

The management question, when trying anything new, is “When does reality trump planning?” For the officials overseeing Healthcare.gov, the preferred answer was “Never.” Every time there was a chance to create some sort of public experimentation, or even just some clarity about its methods and goals, the imperative was to avoid giving the opposition anything to criticize.

[snip]

This is not just a hiring problem, or a procurement problem. This is a management problem, and a cultural problem. The preferred method for implementing large technology projects in Washington is to write the plans up front, break them into increasingly detailed specifications, then build what the specifications call for. It’s often called the waterfall method, because on a timeline the project cascades from planning, at the top left of the chart, down to implementation, on the bottom right.

Like all organizational models, waterfall is mainly a theory of collaboration. By putting the most serious planning at the beginning, with subsequent work derived from the plan, the waterfall method amounts to a pledge by all parties not to learn anything while doing the actual work. Instead, waterfall insists that the participants will understand best how things should work before accumulating any real-world experience, and that planners will always know more than workers.

This is a perfect fit for a culture that communicates in the deontic language of legislation. It is also a dreadful way to make new technology. If there is no room for learning by doing, early mistakes will resist correction. If the people with real technical knowledge can’t deliver bad news up the chain, potential failures get embedded rather than uprooted as the work goes on.

Now read Peter Berkowitz's Obama's Slow Learning Curve.

But perhaps the president’s most astonishing statement involved an insouciant confession of ignorance. Returning to a common but under-appreciated motif of his presidency, Obama remarked: “What we’re also discovering is that insurance is complicated to buy.”

What deficiency of Obama’s education and of the education of those who surround him accounts for administration officials not knowing what is perfectly well-known to most ordinary Americans?

This discovery that purchasing health insurance is complex is just the most recent of the rather stunning lessons that Obama professes to have learned on the job about how the world really works.

Berkowitz then goes on to list and discuss additional things that Obama ended up acknowledging not knowing what he was talking about; Peace between Palestine and Israel - “I think that we overestimated our ability to persuade them to do so when their politics ran contrary to that"; the 2008 stimulus program - “shovel-ready was not as shovel-ready as we expected"; the implementation of the Affordable Care Act - “Now, let's face it, a lot of us didn't realize that passing the law was the easy part.”

Contrary to the president’s breezy attitude suggesting that these drastic miscalculations were not knowable in advance, we know that all were foreseeable because all were perspicaciously foreseen by critics from the beginning. (The only possible exception is the staggeringly inept rollout of the HealthCare.gov website, the magnitude of which caught even the president’s toughest critics off guard.)

It’s a cliché that democracy is messy and difficult; it’s a truism that politics demands the cutting of deals and the hammering out of trade-offs; it’s common knowledge that implementing public policy and conducting diplomacy involve unforeseen obstacles and intricate maneuvering that are hard to grasp from the outside.

Yet all this keeps catching Obama and his aides by surprise. Team Obama’s surprise, however, is really not all that surprising.

Berkowitz's explanation for serial disengagement from reality?

The president and the officials around him are the product of the same progressive version of higher education that simultaneously excises politics from the study of government and public policy while politicizing education. This higher education denigrates experience; exalts rational administration; reveres abstract moral reasoning; confidently counts on the mainstream press to play for the progressive political team; accords to words fabulous abilities to remake reality; and believes itself to speak for the people while haughtily despising their way of life.

The education President Obama received at Columbia University and Harvard Law School -- and delivered to others as a lecturer at the University of Chicago Law School -- encourages the fantasy of a political world subject to almost limitless manipulation by clever and well-orchestrated images. This explains why the harsh exigencies and intractable forces of politics keep stunning the president, each new time as if it were the very first.

Is Berkowitz right? Probably in part. Our best universities do serve as an effective sorting mechanism. You know where to go to find the brightest candidates. But they are not always the most effective or the best. The best of them are able to acquire truly phenomenal educations. But many, regrettably, end up wandering into academic la la land from whence few are known to return with any desirable capabilities and many distorting beliefs.

The infusion of post modernism, critical race theory, gender studies, etc. have put large swaths of reality beyond critical discussion to the great detriment of all. More spectacularly they have created an environment in which the fervor of belief is allowed to supersede logic and evidence. It is a somewhat ironical turn of fate that segments of the academy are the ones so married to an entirely faith-based postmodernist secular creed whose foundations are patently separated from reality. Is it any wonder that the products of such education can find themselves in such deep water when their fervid belief that failure is not an option turns out to be founded on quicksand.

Reality is a cruel mistress to the post modernist faithful.

when we moralize, we are monotheists

From Maxims and Reflections by Goethe.

When we do science, we are pantheists;
when we do poetry, we are polytheists;
when we moralize, we are monotheists

Tis the good reader that makes the good book

From Society and Solitude by Ralph Waldo Emerson.

Tis the good reader that makes the good book; in every book he finds passages which seem confidences or asides hidden from all else and unmistakenly meant for his ear; the profit of books is according to the sensibility of the reader; the profoundest thought or passion sleeps as in a mine, until it is discovered by an equal mind and heart.