Articles from the Institute Letter

Additional articles from new and past issues of the Institute Letter will continue to be posted over time and as they become available.

By John Hopfield

From Rudyard Kipling's "Just So" story "The Elephant's Child"

All of us who have watched as a friend or relative has disappeared into the fog of Alzheimer’s arrive at the same truth. Although we recognize people by their visual appearance, what we really are as individual humans is determined by how our brains operate. The brain is certainly the least understood organ in the human body. If you ask a cardiologist how the heart works, she will give an engineering description of a pump based on muscle contraction and valves between chambers. If you ask a neurologist how the brain works, how thinking takes place, well . . . Do you remember Rudyard Kipling’s Just So Stories, full of fantastical evolutionary explanations, such as the one about how the elephant got its trunk? They are remarkably similar to a medical description of how the brain works.

The annual meeting of the Society for Neuroscience attracts over thirty thousand registrants. It is not for lack of effort that we understand so little of how the brain functions. The problem is one of the size, complexity, and individuality of the human brain. Size: the human brain has approximately one hundred billion nerve cells, each connecting to one thousand others. Complexity: there are one hundred different types of nerve cells, each with its own detailed properties. Individuality: all humans are similar, but the operation of each brain is critically dependent on its individual details. Your particular pattern of connections between nerve cells contains your personality, your language skills, your knowledge of family, your college education, and your golf swing.


By Brandon C. Look

While all previous philosophers were, in (above) Immanuel Kant’s mind, guilty of various errors, Gottfried Wilhelm Leibniz occupied a special position in his conception of the history of philosophy and the history of reason’s pretensions.

If the eighteenth century is to be seen as the “Age of Reason,” then one of the crucial stories to be told is of the trajectory of philosophy from one of the most ardent proponents of the powers of human reason, Gottfried Wilhelm Leibniz (1646–1716), to the philosopher who subjected the claims of reason to their most serious critique, Immanuel Kant (1724–1804). Not only is the story of Kant’s Auseinandersetzung with Leibniz important historically, it is also important philosophically, for it has implications about the nature and possibility of metaphysics, that branch of philosophy concerned with fundamental questions such as what there is, why there is anything at all, how existing things are causally connected, and how the mind latches onto the world. Like many philosophical debates, however, it is also prone to a kind of “eternal recurrence” to those who are ignorant of it. 

Leibniz was a “rationalist” philosopher; that is, he was committed to two theses: (i) he believed that the mind has certain innate ideas—it is not, as John Locke and his fellow empiricists say, a tabula rasa or blank slate; and (ii) he believed in—and, in fact, made explicit—the “principle of sufficient reason,” according to which “there is nothing for which there is not a reason why it is so and not otherwise.” This principle had enormous metaphysical consequences for Leibniz, for it allowed him to argue that the world, as a series of contingent things, could not have the reason for its existence within it; rather there must be an extramundane reason—God. Further, as a response to the mind-body problem, Leibniz advanced the theory of “pre-established harmony,” according to which there is no interaction at all between substances; the mind proceeds and “unfolds” according to its own laws, and the body moves according to its own laws, but they do so in perfect harmony, as is fitting for something designed and created by God. Strictly speaking, however, Leibniz was not a dualist; he did not believe that there were minds and bodies—at least not in the same sense and at the most fundamental level of reality. Rather, in his mature metaphysical view, there are only simple substances, or monads, mind-like beings endowed with forces that ground all phenomena. Finally, according to Leibniz, since these simple substances are ontologically primary and ground the phenomena of matter and motion, space and time are merely the ordered relations derivative of the corporeal phenomena. Leibniz contrasted his view with that of Isaac Newton, according to whom there is a sense in which space and time can be considered absolute and space can be considered something substantial.


By Helmut Hofer and Derek Bermel

This image (produced with a Java applet by Alec Jacobson at http://alecjacobå shows color­ful trackings of the paths of satellites as they evolve from a simple single orbit to a complex multicolored tangle of orbits.

I can’t understand why people are frightened of new ideas. I’m frightened of the old ones.—John Cage

Helmut Hofer, Professor in the School of Mathematics, writes:

Last September, the School of Mathematics launched its yearlong program with my Member seminar talk “First Steps in Symplectic Dynamics.” About two years earlier, it had become clear that certain important problems in dynamical systems could be solved with ideas coming from a different field, the field of symplectic geometry. The goal was then to bring researchers from the fields of dynamical systems and symplectic geometry together in a program aimed at the development of a common core and ideally leading to a new field—symplectic dynamics.

Not long before, in my 2010 inaugural public lecture at IAS, “From Celestial Mechanics to a Geometry Based on the Concept of Area,” I had described the historical background and some of the interesting mathematical problems belonging to this anticipated field of symplectic dynamics. The lecture began with a computer program showing chaos in the restricted three-body problem. This problem describes the movement of a satellite under the gravity of two big bodies, say the earth and the moon, in a rotating coordinates system in which the earth and the moon stay at fixed positions. The chaos in the system is illustrated by putting about ten satellites initially at almost the same position with almost the same velocity.

When the system starts evolving, the program shows colorful trackings of the paths of the satellites as they evolve from a simple single orbit to a complex multicolored tangle of orbits, once the orbits of the different satellites start separating.


By Graham Farmelo

Faculty and Members at IAS witnessed the announcement of CERN's discovery of a Higgs-like boson in Bloomberg Hall and later celebrated with macerated strawberries, Higgs-denoted cookies, and a Peeps-populated diorama (above) of CERN’s ATLAS particle detector, created by Marilena LoVerde, Member in the School of Natural Sciences, and Laura Newburgh, a physicist at Princeton University

On Wednesday, July 4, shortly after 4 a.m., the Institute’s new Director, Robbert Dijkgraaf, was in Bloomberg Hall, cracking open three bottles of vintage champagne to begin a rather unusual party. He was among the scientists who had been in the Hall’s lecture theater since 3 a.m. to watch a presentation from Geneva on the latest results from the CERN laboratory’s Large Hadron Collider. In the closing moments, after CERN’s Director-General Rolf Heuer cautiously claimed the discovery of a new sub-atomic particle—“I think we have it, yes?”—applause broke out in the CERN auditorium and in the Bloomberg Hall lecture theater. Within minutes, the IAS party was underway.

The new particle shows several signs that it is the Higgs boson, the only missing piece of the Standard Model, which gives an excellent account of nature’s electromagnetic, weak, and strong interactions. Although some physicists had come to doubt whether the boson existed, Nima Arkani-Hamed, Professor in the Institute’s School of Natural Sciences, was so confident that in 2007 he bet a year’s salary that it would be detected at the Large Hadron Collider. In the week before the CERN presentation, Arkani-Hamed invited colleagues to the party and organized the catering. Convinced that he had won his bet, he bought three bottles of champagne, including two of Special Cuvée Bollinger.


By Israel Gershoni

Ruz al-Yusuf reacting to the outbreak of the Second World War. “History repeats itself: The end of Hitler at the hands of democracy.” Britain, France, and Egypt portrayed as Allied Forces against Nazi Germany. September 9, 1939.

“Freedom is the ultimate virtue of mankind”; “Democracy is the only political system of modern man and modern society”; “Therefore, Egypt must be committed to freedom and democracy.” These are the words of ‘Abbas Mahmud al-‘Aqqad in his book Hitlar fi al-Mizan (Hitler in the Balance), which aroused sharp public interest in Egypt and the Arab world when it was published in Cairo in early June 1940. The book was written when Hitler was at the height of his military successes, and it was widely assumed that nothing would thwart his advances. ‘Aqqad’s book leveled a harsh attack on Hitler and Nazism. Through his analysis of Hitler’s complex and deranged personality, ‘Aqqad deconstructed Nazi racism, dictatorship, and imperialism. He portrayed Hitler and Nazism as the ultimate danger not only for freedom and democracy, but also for modernity, the very existence of modern man and enlightened culture. In ‘Aqqad’s view, the merits of a liberal democracy were rooted in: individual freedoms and civil liberties, constitutionalism, a parliamentary and multiparty system, the separation of powers, equality for all citizens, cultural pluralism, and the unquestionable legitimacy of political opposition.

When ‘Aqqad (1889–1964) expressed these views in the early years of the Second World War, his liberal democratic worldview had fully coalesced. Already in his early fifties, he was an established and well-known intellectual active for more than three decades. In hundreds of articles published in the Egyptian press, and particularly in his book The Absolute Rule of the 20th Century (al-Hukm al-Mutlaq fi al-Qarn al-‘Ishrin), published in 1929, ‘Aqqad reaffirmed his commitment to democracy and his rejection of any form of absolutism, oligarchy, aristocracy, and autocratic monarchial rule, and in particular Fascism, Nazism, and, in a different way, Communism. As a representative of the Wafd party in the Egyptian parliament, and later as the intellectual leader of the Sa‘adist Party and its representative in the Chamber of Deputies, ‘Aqqad was one of the most consistently democratic activists in Egyptian politics and culture.