Plato’s Cave

Plato's CaveA Greek philosopher, Plato lived in the years around 400 BC. He is noted for many ideas, some of which usually emerge in a discussion of education.

In one of his works, The Republic, he defines his just society. In it he presents what has come to be called the Allegory of the Cave.

According to Plato the cave is occupied by slaves who are chained so that they face the inner wall and cannot see outside the cave. There is a fire behind them that causes the life outside to be reflected on the wall. As a result the slaves can only see the shapes or outlines of all real life as they are reflected on the wall. If a slave one day escapes and goes outside he will see the real world of plants and animals and all other things. If he decides to re-enter the cave and enlighten his fellow slaves he may risk his life since his message may threaten the slaves’ hardened view of reality.

In Plato’s just society there are three groups of citizens.

The producers

  • are in all professions other than warrior and ruler,
  • have no share in ruling, but merely obey what the rulers decree.

The auxiliaries are

  • the warriors,
  • responsible for defending the city from invaders, and for keeping the peace at home,
  • must enforce the convictions of the guardians, and ensure that the producers obey.

By age thirty-five, after an appropriate education, which includes mathematics, gymnastics, and the techniques of philosophical discovery, the auxiliaries are ready to educate the producer class and “lead them from the cave”. By age fifty they are ready to join the guardian class.

The guardians are

  • responsible for ruling the city,
  • are known as philosopher-kings.

In Plato’s model, society is permanently stratified and power is in the hands of the philosopher-kings.

Some have suggested that today’s ubiquitous digital screens may be causing viewers to see only the shapes of the world’s reality.

A Good Start to Your Lesson: Stimulating Interest and Enthusiasm

“Welcome to my job!” —Comedian George Carlin at the opening of his show.

Teslas's Lab
Nikola Tesla’s Lab, Colorado, 1899

The start of anything is always an important opportunity to set the tone for what follows. In teaching, particularly, a good opening can determine the eventual success of the classroom experience.

By the time you meet them your students have acquired the skill of adaptation. They adapt to each new school, each new teacher, and each change in curriculum and teaching technique. When they end up in your class they are expecting more of what they have already lived and are preparing to adapt once again. Good class beginnings can break this pattern, generate interest and enthusiasm, and encourage engagement.

Ideally students will come to your class wondering what unusual thing will happen today. Imagine that for your first lesson on the Greek philosophers they arrive in class to see you wrapped in a bed sheet ready to read directly from Aristotle as he would have spoken in the Greek agora. (Or maybe it is your students who are invited to come dressed for the occasion.)

The great minds of any discipline are, after all, people, and many have led interesting or complicated lives. This makes biographies a great source of interest. Since when are Canadian women persons under the law? Since 1929, thanks in large part to the country’s first female magistrate, Emily Murphy and four other “persons” who took the case to the British Privy Council. Women had previously been barred from being Senators or even attending court cases because they were not deemed to be persons under Canadian law.

Inventor Nikola Tesla was a contemporary of Thomas Edison. He acquired a long list of patents, greatly influenced the design of the electric power grid in North America, and anticipated devices like the cell phone. Tesla was also a fastidious dresser and always arranged to be photographed from his good side.

Story, or narrative, is a powerful way to bring history to life. Perhaps a modern headline would lead to curiosity about one of history’s best known philosophers: Greek Teacher, Accused of Corrupting Youth, Commits Suicide at Age 71.

It is useful to have a repertoire of personal stories that have been well received in the past. Practice them and use them when appropriate. Humorous is good although humor can sometimes be dangerous. The safest way to use humor is to ensure that you are the butt of the joke. And Mother’s advice still stands: stay away from sex, politics, and religion. A good story has a beginning and a middle which build to a strong punch line, rehearsed and well delivered. Good stories are short and contain no unnecessary details. It is an art that is worth practicing and is a great way to get things started.

Demonstrations are also powerful ways to begin. I will never forget the high school chemistry teacher who managed to create a small explosion while introducing his lesson. Attention was keen for the rest of the class (especially in the front row). A prof at teachers’ college set a hard-boiled egg on top of an empty milk bottle and asked how we might get the egg into the bottle without breaking it. When no correct answers emerged he set fire to a piece of newspaper, dropped it into the bottle, and replaced the egg. Within a few seconds the egg slammed into the bottle with a bang and settled there unbroken. Attention was keen for the rest of the class (especially in the front row).

How about posing a problem? In the absence of a speedometer, why might it be difficult to calculate the speed of a car at an instant in time? Or, How can a country best balance the civil liberties of individuals against the need for security?

If, in the previous class meeting, you asked for feedback from your students you could share some of it, along with your comments, at the opening of the next session.

In one course I taught I began each class with a very short book review. I pulled something off my bookshelf and explained to the class how it had been valuable to me.

Displaying quotations at the outset, and possibly having a short discussion, can get minds engaged and ready to tackle other ideas.

The secret of life is honesty and fair dealing. If you can fake that, you’ve got it made.—Groucho Marx

I had a university professor who always had music playing before he started his lecture (to a small, intimate group of 600 students). I never found out why he did this butI read subsequently that he had received an award for being one of the best teachers in the entire university. (I just told you a story 🙂  ).

For the braver teacher you might want to ask, “Has anyone heard any news today that they are concerned or excited about?”

The possibilities for openers are, of course, unlimited. It’s worth noting that openers are part of our normal way of coming together with other people. We do it with colleagues and friends, usually automatically. Some people might even be offended if you didn’t begin your conversation with an interesting warm-up, before getting down to business.

We often fall into the trap of thinking that teaching a class comes with restrictions that impose a formality not typical of our daily human interactions. Teaching a class is not just a meeting of the minds but a coming together of many other things that we share as humans. A class may struggle to really get going if we forget to relax and enjoy a few human moments at the start.

Let’s Sleep On It

“The clearest finding is that sleep does not serve just a single purpose. Instead it appears to be needed for the optimal functioning of a multitude of biological processes—from the inner workings of the immune system to proper hormonal balance, to emotional and psychiatric health, to learning and memory, to the clearance of toxins from the brain. At the same time, none of these functions fails completely in the absence of sleep. In general, sleep seems to enhance the performance of these systems instead of being absolutely necessary. And yet anyone who lives for months without sleep will die.”Robert Stickgold, Scientific American, October 2015

Borg Regenerating
Borg Regenerating
Sleep deprivation and the effects of reduced amounts of sleep are now being studied seriously at several universities. According to Robert Stickgold, director of the Center for Sleep and Cognition at Beth Israel Deaconess Medical Center, lack of sufficient sleep reduces the creation of antibodies produced by vaccination and thereby undermines their effectiveness, reduces the ability to clear glucose from the blood (the function of insulin), increases blood levels of the appetite-stimulating hormone ghrelin, and decreases the quantity of a hormone called leptin which inhibits hunger by signaling the brain that there is no need to eat. The results are increased feelings of hunger which contribute to obesity.

Other research suggests that memory fixation occurs during sleep and that with sleep deprivation we are likely to form twice as many memories of negative life events as of positive events. This results in biased, and potentially depressing, memories of the day’s events.  Under certain circumstances, this can lead to major depression and may contribute to other psychiatric disorders as well.

An important finding for educators is that sleep after learning leads to the selective stabilization, strengthening, integration and analysis of new memories. In this way sleep controls what we remember and how we remember it. It also prevents the deterioration of memories over time and can actually improve them. It selectively strengthens memories that our brain deems valuable. What is valuable for the brain is information that can help enhance future performance.

Other lines of research are exploring the implications of the increase in inter-cellular space that occurs in the brain during sleep. This results in a better flow of cerebrospinal fluid between the brain and the spine. Experiments with mice demonstrate that betaamyloid (the precursor of the amyloid plaques found between neurons in the brains of Alzheimer’s patients) is cleared from the brain during sleep at twice the rate seen in awake animals.

Overall, the results of studies on the role of sleep in hormonal, immunological and memory functions suggest that a lack of sufficient sleep could result not only in being very tired, but sick, overweight, forgetful and very blue.

Black Holes and General Education

“Only two things are infinite, the universe and human stupidity, and I’m not sure about the former.”—Albert Einstein.

Albert Einstein
Albert Einstein

College students in Quebec, Canada find that their chosen program of study always includes General Education courses in Humanities, English, French, and Physical Education.

While there is some controversy about the General Education requirement educational authorities continue to see benefit in it, perhaps in preparing graduates who are “better rounded” and able to continually enrich their own lives as adults.

While languages, Humanities, and Physical Education seem reasonable inclusions in General Education, excluding other disciplines from the core curriculum may leave students with important gaps in their understanding of the physical world.

It has been just over a hundred years since Albert Einstein experienced a series of eureka moments that overthrew conventional understandings of our universe. Despite the overwhelming impact of his Special Theory of Relativity and, four years later, his General Theory of Relativity most students  studying a century later know little of such important notions as spacetime and gravity.

Scientists had come to understand gravity as a pull to Earth and later, thanks to Isaac Newton, as a force of attraction between any two masses. Then came Albert Einstein. In 1915 he revealed, in his general theory of relativity, that gravity is not a force so much as the by-product of a curving universe. In other words, what we think we know about gravity from everyday experience is wrong.

Einstein’s spacetime continuum connects the three dimensions of space to time as the fourth dimension. To describe the position of any object we have to define its distance from the three axes of 3D space but also indicate when, in time, it was there. This seems counter-intuitive since we customarily think of time as a totally separate dimension from space. For Einstein it is seamless and endless.

Spacetime can be compared to a large mattress which is easily compressed by a large object such as a bowling ball. The depression made by the bowling ball creates a curvature in the “spacetime” mattress. Any neighbouring small objects will naturally roll toward the depression. In short, it is the presence of large objects in the cosmos which bends the spacetime continuum and creates the effects we call gravity. The curvatures of spacetime dictate the movements of the heavenly bodies and create our sensation of always being pulled to the ground. Even light can be bent to follow its contours.

In the wake of Einstein’s work Physicists grapple with a number of problems. The various beaviours of matter in the universe require at least two separate theories to explain them. Relativity and Quantum Mechanics cannot yet be harmonized to produce one theory of nature, sometimes referred to as the Theory of Everything. In addition, more recently explored phenomena must be incorporated into whatever theory will triumph. These include dark energy, dark matter, and dark holes. Understanding dark holes, which are plentiful and far away, is important in building and correcting theories that describe our universe.

Do the implications of Einstein’s work constitute important general knowledge in the same way we now understand that the earth is round and that we are not at the center of our galaxy?

General Education implies general knowledge. The difficult question is, “What constitutes an adequate general knowledge?” The answer is complicated by the fact that it changes, almost daily.

Evolving Cognitive Skills: The Flynn Effect

The Flynn effect is the substantial and long-sustained increase in both fluid and crystallized intelligence test scores measured in many parts of the world from roughly 1930 to the present day. When intelligence quotient (IQ) tests are initially standardized using a sample of test-takers, by convention the average of the test results is set to 100 and their standard deviation is set to 15 or 16 IQ points. When IQ tests are revised, they are again standardized using a new sample of test-takers, usually born more recently than the first. Again, the average result is set to 100. However, when the new test subjects take the older tests, in almost every case their average scores are significantly above 100.—Wikipedia

IQ Curve
IQ Curve

Based on the results of new test-takers on standard IQ tests James Flynn (see Ted talk, 2013) has postulated that we are getting cognitively more intelligent with time. What is interesting are the ways in which our cognitive skills seem to be evolving.

Flynn cites three main evolving cognitive skills:

  1. the ability to classify
  2. the use of abstraction shaped by logic
  3. taking the hypothetical seriously

These are illustrated by examples. In the first case, a man of a previous generation is asked, “What do a crow and a fish have in common?” The man sees nothing in common: one flies, one swims, and so on. When asked if the crow and the fish are not both animals, the man says, “no, one is a fish and one is a crow”. He sees only how the creatures exist in his own concrete world and cannot see the common features that would enable their classification as animals.

An inability to use abstraction governed by logic is illustrated in this example. A man is told, “There are no camels in Germany. Hamburg is a city in Germany. Are there any camels in Hamburg?” The man speculates that there might be, if the city is large enough. He is incapable of following the logic of the verbal abstraction.

In the third case a subject is told, “At the North Pole there is always snow. Wherever there is always snow the bears are always white. What color are the bears at the North Pole?” The subject replied that one would have to go and verify. He, himself, had only ever seen brown bears. He wondered why anyone would waste time on such a problem. As a further example of a lack of respect for the hypothetical he describes the reaction of his racially-biased parents to the question, “How would you feel if you woke up black and were treated as inferior?” The response was laughter and, “When was the last time someone went to bed and woke up black?”. No respect for the hypothetical.

These three cognitive skills, the ability to classify, the use of abstraction shaped by logic, and taking the hypothetical seriously appear to be the major factors which differentiate our cognitive abilities from those of our grandparents. These same skills are essential to doing science and, as Flynn maintains, engaging in moral argument.

He also notes that now fully a third of us are engaged in cognitively rich professions and that most professions are undergoing upgrade to become more and more demanding of the cognitive skills described above.

Related: PISA: New Skills Measured in International Student Test


Screens and Children

A revolution encompassing all humanity. Nothing will be as it once was. We are facing some real mutants. — psychiatrist Boris Cyrulnik

Screen Baby
Screen Baby

Teachers and parents know that today’s children are not quite like their predecessors. Much has been said about the impact of digitally powered  screens on the capabilities, attitudes, and habits of today’s young people. The views fall into three categories: appreciation of new talents, horror at the current state of childhood, and simple resignation.

Babies are born into a world of “screens”. Some indications suggest that at school age children will spend five hours a day using one. In college, they will use a laptop to send over 80 text messages a day.

The optimistic observers see “digital natives” who are curious, energetic, fluid, and rapid. They point out that new technology anxiety goes back to Socrates and his fear that writing would adversely affect people’s memory.

Nonetheless, Oxford neurology professor Susan Greenfield claims, “When they surf the Web or play on the Web, their brain, which is under construction, is exposed to an activity that is so intense that it disrupts their development.” This can result in difficulties concentrating, communicating with others, projecting themselves, and lack of empathy. Some claims have even been made about a general decline in IQ. (This is a contentious assertion. For an intelligent discussion of our cognitive history see James Flynn’s Ted Talk.)

Other researchers examine the effects of different tools on the brains of children having observed that pianist- and violinist-brains are imprinted differently. Unlike the brain of the “print” era (reflective, linear, slow, accumulating intelligence) the screen brain is more fluid, rapid, fragmented, and automatic. These changes correspond to a shift in the location of brain activity from the pre-frontal cortex (site of self-awareness, judgment, and abstraction) to the posterior regions, involving visual and sensorial parts of primary intelligence.

Other brain-based concerns focus on the addictive use of screens. Excessive use (according to some, more than nine hours per week) leads to an increase in the size of the brain’s reward system. Some research shows that children addicted to screens secrete dopamine in a way similar to other addicts.

There are other fears as well. A child addicted to screens may be less motivated to exercise his body or his imagination, to produce his own mental images, to amuse himself, or to tolerate suffering or frustration. He may no longer know how to play, an activity essential to developing imagination, a sense of humor, and ultimately, a means of avoiding depression.

Parents, and many others, accept the proliferation of screens as simply inevitable and a sometimes cure for children’s boredom. The take-away from all of this may be that the human brain, like all other elements of our physiological, psychological, and societal structures, evolves in response to changing times. This raises the question, “What is it about the nature of our times that favors brains that are more curious, energetic, fluid, and rapid as opposed to reflective, linear, slow, and intelligence accumulating ?” Educators must wonder, as well, what does teaching entail when the basic learning apparatus has changed from the days of their youth.

The Great Idea of Parker Palmer

Current pedagogical debate often focuses on the shift from teacher-centered learning to student-centered learning. The former is characterized by the Mathematics professor who says, “Our primary responsibility as mathematicians is not to students but to mathematics: to preserve, create, and enhance good mathematics and to protect the subject for future generations.” At the other end of the debate, we risk “mindless relativism” and teachers yielding “too much of their leadership; it is difficult to confront ignorance and bias in individuals or the group when students themselves comprise the plumb line.” —Parker Palmer, The Courage to Teach

Parker Palmer
Parker Palmer

To understand Palmer’s view requires an understanding of the “Great Idea”. He says,”If we want a community of truth in the classroom, a community that can keep us honest, we must put a third thing, a great thing, at the center of the pedagogical circle. When student and teacher are the only active agents, community easily slips into narcissism, where either the teacher reigns supreme or students can do no wrong. This can lead to disinterest and poor engagement on the part of learners or to a teacher’s capitulation to relative truths where everyone has their own truth. A learning community that embodies both rigor and involvement will elude us until we establish a plumb line that measures teacher and students alike—as great things can do.”

This is what Palmer calls a subject-centered approach.  The great idea is the topic, or the discipline, under examination. In Physics it might be Newton’s Third Law, in Literature it might be the use of foreshadowing in a Shakespearean play. Such great ideas have motivated great teachers when they were students. They are the concepts, theories, and techniques that teachers love to teach because they hold some special value or significance in the world.

Putting the Great Idea at the centre of classroom activity means that the idea itself becomes the source of all truth about it. Teacher and students are co-learners who can never exhaust all the worthwhile inquiry into the subject. In this way the subject ceases to be a second-hand account of some isolated and distant reality and comes alive as yet another important human phenomenon.

PISA: New Skills Measured in International Student Test


This Fall (2015) the PISA (Program for International Student Assessment) exam will test tens of thousands of 15-year-old students in 51 countries on reading, math and science.

A new and controversial series of questions to measure collaborative problem solving skills will evaluate the outcomes of games, jigsaw puzzles and experiments accomplished with the help of a virtual partner. The belief is that working with unseen partners, especially online, is becoming an essential skill for career success. It is the way of the future in the workplace.

Countries motivated by international competitiveness and, notably, companies like  Cisco, Intel and Microsoft, are promoting “21st-century skills” for new employees: the ability to think critically and creatively, to work cooperatively, and to adapt to the evolving use of technology in business and society.

The 15-year-old PISA exam, coordinated by the Organization for Economic Co-operation and Development (OECD), a coalition of 34 member countries and their industrial leaders, now tests a more specific set of skills—group problem-solving using the Internet. PISA officials believe this addition will push governments to better prepare their young people to function in the global economy. Participants will record outcomes of games, solve jigsaw puzzles and perform experiments in collaboration with a virtual partner while communicating through a chat box. This addition to the test is based on the belief that working with partners online will be the norm in the workplace of the future.

One criticism of the new question domains is that problem-solving skills may not be the same across disciplines, even though John Dewey and others have insisted that they are.

Test scores on the 2012 test
Test scores on the 2015 test