Saul G. Cohen Brandeis University Woltham, Massachusetts 02154
I had come to Haward in 1933, not knowing what chemistry was at all. As a student in Professor Lamb's freshman course, I thought him elderly and benign, fascinated by the phenomena and regularities of chemistry, happy to share his pleasure in the subject with us. But there was a remarkable dichotomy in the course. The section was taught by bright, tense, young postdoctorals. They talked about the new chemistry, the Bohr atom and the developments from it, the applications of quantum theory. They showed intense interest in the developing science, pleasure in bringing us into this new world, and dissatisfaction due to inadequate opportunities in that period of the Depression. Nevertheless their deep interest in the subject and in teaching us seemed to be in contrast with the attitudes I had observed in my brief exposure to other areas, which I had considered, and I opted to concentrate in chemistry. The problems and difficulty in teaching and learning chemistry became apparent to me early: the basically abstract nature of the subject, abstract notions of atoms and molecules, and the observable phenomena to he described and dealt with in terms of abstract formulations; and the tensions between past, present, and future in this art. The latter became apparent again in the advanced organic chemistry course. Professor Kohler gave a masterful series of lectures, describing, it seemed, a mature body of knowledge, admirably developed, establishing for us that chemistry, with its ideas of structure and change, was a fundamental, powerful, intellectual achievement. A few years later the same course was taught by Paul Bartlett. It was very different in character. Not neglecting the past, it emphasized current problems, bringing to the fore the developing character of chemistry. In this, Paul Bartlett made a most important contribution to the teaching and practice of organic chemistry, and this merits great recognition. In teaching, past accomplishments must he selected carefully, not only and perhaps not largely for content, but to illustrate how problems are recognized, perceived differently at different times, and developed. The difficult teaching of the techniques of contemporary problem solving must also he dealt with hut this may not become the entire task. I remember, in another course, the young professor confided to us in the opening lecture that we would not he able to understand the subiect. This was what I heard and believed; it became a selflfulfilling prophecy. At Christmas time I decided I had better understand the course. There is a difference between understanding a course and understanding a subject. The course is what is covered and can be understood. The subject has an infinite aspect to it. In teaching over a long period, we sense more deeply the essence, the complexity, the nuances. What we thought and said with some confidence a t an earlier date we are no longer sure of, and what we seem to he sure of will probably not he valid later. Teaching becomes learning for the teacher as for the student, but the student should not be overly confused by the teacher's uncertainty. Our understanding changes, perhaps by a cessation of stupidity; we derive pleasure from a new insight, and from Taken lrom the Norris Award Adaress, November 9,1972 820 /Journal of Chemical Education
and Teaching the opportunity to share it, and recognize that it is merely the best view that we may have a t the time, and that it too will change. At any time we have different levels of understanding of different parts of our subject. We prepare an appropriate smorgasbord, giving some superficial lectures on new material, more comprehensible and satisfying lectures on material of which we may have a deeper understanding. In connection with the current high and deserved interest in medical education, I remember a young instructor who took me aside when I was a senior to give me advice. He assured me that I probably was not stupid, since my academic record was excellent, but that my talent did not lie in chemistry, and I should go to medical school. He surely was concerned only with my welfare-there would be no possibility of suitable employment for me in chemistry. And it was true also that I was not a particularly talented chemist. Thus I learned that if something is true one doesn't have to say it. And further one never knows the whole truth. What evidence was there that I would have talent in medicine? With what assurance can one apply statistical truth to an individual case? However my applications to a dozen universities for a graduate teaching assistantship in chemistry were unsuccessful. That instructor's advice was discouraging, but it seemed sound. As a graduate student a t Haward I learned to draw my own conclusions, and not to accept prior authority, an attitude which seems to come to me easily, but which I nevertheless have to relearn continuously. It is important to teach students to make their own observations, describe them accurately, draw independent inferences, act on them, and accept proof or disproof of the inferences. This kind of training need not he restricted to the natural sciences. The need to try to see and formulate prohlems and consequences of recommended action, as they are, and not as you wish them to he, not as someone else says they are, or wishes them to be, or wishes you to think they are, that need is common to our condition, and the ability to carry out this formulation is essential for solution of any problem. In science we are generally restricted and helped by a reality boundary. Nonsense will out. Physical reality will bring us up short, if we have assessed the situation inaccurately and our conclusions and actions were based on faulty analysis. In the non-sciences the initial description may be difficult, the evaluation of the indicated action a long time coming, and self-service may insist on the truth of plausible falsity. Nevertheless the tasks are similar and solutions in all areas depend on what may seem to he homely virtues, honesty in observation, wisdom in evaluation, discounting of prejudgement, willingness to admit error. It is not an easy process. Perception and choice of a problem, setting of a goal, are strongly influenced by values and emotion. The solution, the road to the answer is largely a rational process, with contributions from experience, which we often term intuition. My first opportunity to teach was given me by Paul Bartlett. There were interesting decisions involved in this. Jobs were indeed scarce and there were two other very highly qualified candidates on hand, Saul Winstein and Robert Woodward. In less than a year all three of us were given this appointment-as instructor in the Advanced Organic course. That was spreading the butter thin. Part
of the task was t o give weekly Saturday morning lectures. I prepared a whole series of lectures, appeared for the first class, and began to talk. When I looked up a t the dazed students an hour later I realized I had completed the entire course; the students were lagging behind. I explained, coolly I hope, that I had summarized the material to he covered and would elaborate in succeeding meetings. From this I learned that repetition might he useful in teaching, and that I should conserve what little capital I might have. I am still nervous a t the first meeting of a course. This position also gave me the opportunity for my first independent research (I). Cleavage of the alkyl-oxygen bond in hydrolysis of esters had been shown not to occur generally. That was a proven, accepted mechanistic conclusion, rare for those days. Showing as we did that it did occur where you might expect it to, and that this too would he general, was to me, what Abraham Maslow later termed a peak experience. It established for me, within me, an identity, in which previously I could not have been confident, that I would be able to do original scientific work. The need to reestablish this confidence recurs however. After a period working on war gases, in which I developed respect for the physiological action of simple chemical compounds, I went to U.C.L.A. as a National Research Council Fellow. I did some experiments and published a paper showing that the acetolysis of certain simple esters could lead to carhonium ions (2). I may have been ahead of the times or perhaps beyond my depth. Many years later Saul Winstein kindly reminded me of the impact of this work on him. This problem has of course been worked on exhaustively by others and that work has led to much fascinating chemistry. It has probably arrived now to a point of diminishing returns. I also published on experiments leading to the activation energy of chain propagation in radical polymerization (3). This work was .subtle, a first approximation, and might have been explored further, but better techniques were introduced by others. Herman Mark, whom I had not yet met, read the article and sent me a kind, flattering note, the only one I think that I have ever received. A few years later I arrived late a t a lecture on polymerization being given by a bright young man. It seemed to me that he was talking about the problem I had worked on, and subtle as it was, was getting it just wrong. During the question period, I hesitantly asked for clarification. Somewhat testily, I thought, he persisted in his way, and assured me that I would find it all explained his way in a paper by one S. G. Cohen. It was a rare opportunity to demonstrate my tact. During my brief stay at U.C.L.A. a bright, gentle, diffident undergraduate would come in and chat with me, about my work, and about chemistry. He later confided that this influenced him greatly, and encouraged him to go to graduate school. He was Ernest Grunwald. Thus my greatest success as a teacher was quite inadvertent. Here was a student who learned and taught far more than the teacher. My education was then furthered by a period in industry, 1944-1950. Many of my friends at Polaroid look on me as a teacher in my relation to them, hut I have learned far more from them than I taught. It is fascinating to observe invention, ingenious, original daring study and use of nature, to be involved in an attitude that you can solve any problem. Describe i t accurately and operationally, think carefully, believe it is important, work without surcease, accept that there are many ways to arrive at the solution. Nature is subtle, resistant hut not hostile, neutral, and will reveal its secrets to the worthy suitor. This of course describes and pertains in general to that aspect of learning which is sometimes classified as research or scholarship, which may he carried out a t the
desk or in the laboratory, alone or with graduate students and colleagues. In this experience one learns how difficult i t is to formulate a significant prohlem, to devise critical experiments, to interpret them properly, and to reformulate the prohlem in the light of experience. Original learning is a t once sobering and the greatest of fun, transforming the participant by total involvement. It may he carried out without direct reference to classroom teaching, hut experience with it has a fundamental effect on teaching-not only in providing the substance, hut also in giving a proper respect for knowledge and the difficulty in attaining it, and a skepticism about facile answers. There is much thought given now to participation by students in university governance. Students are a vital part of, the basic reason for the very existence of, the university. They are affected by what is done there and have every right to express their desires and be listened to carefully. They may be most perceptive in bringing to attention prohlems, needs, injustices, though like their elders not always nor entirely unselfishly. It often proves easier for them to work on the forefront of knowledge, unhampered by excess expertise and involvement in old concerns. But there is a limit to what the old can learn from the young, beyond that which I have indicated, important as that may he. Basically we cannot learn from them what to teach them-we all teach best what we know, at some level of comprehension; we know what we learn, and learning is hard to come by, a slow and often lonely process. The bald statement of a problem or need, which we frequently hear, is a far cry from a solution or even from an operative description of the prohlem which may lead readily to an inference as to an appropriate course of action. This is not to say that problems should not be proclaimed and worked on-they must be. Experience in solution of even scholarly prohlems indicates that answers are not obvious and may be surprising. Those without this experience, in such depth that it affects their responses, underestimate the complexity. But many who apparently have this experience make the same error. Nevertheless, individual scholarship, internalization of the difficulty and fun experienced in the path from original question to original answer, learning, is useful and important in preparing oneself to seek answers to problems, and in teaching-and teaching should he learning, on both sides of the lectern. Think what we learn when we teach about some problems in stereochemistry. The tetrahedral carbon atom was accepted almost 100 years ago. Ball and stick models were available to anybody. The model of cyclohexane stood before one's eyes, puckered. Yet it took years for it to be accepted that cyclohexane was not planar. The axial and equatorial suhstituents stood there for all to see (4, 5). Yet i t took many years (6)and sophisticated electron diffraction studies by Hassel (7) to teach this lesson; and more years for Barton (8) to learn and teach the relation of chemical reactivity to this structural feature. Consider another example. Most simple optically inactive organic compounds have carbon atoms with three different suhstituents. This includes essentially all organic compounds except the relatively small.number which are either very small, very simple, or very symmetrical. In this vast array of compounds, which lack a simple axis of symmetry, the carbon atoms which have three different suhstituents have two apparently identical suhstituents. But these two substituents are not identical. Simple examination of the ball and stick models indicates that the two similar suhstituents are enantiomeric. Reaction at one substituent leads to one compound, reaction at the other substituent leads to the mirror image (9). The great significance of this is that once any optically active molecules were formed, in the primordial ooze, possibly by some polarization or other physical effect, their interaction with the vast array Volume 50, Number 12, December 1973
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of pro-chiral species would be diastereomeric and lead to optically active species. Elaboration would lead to optical activity-everywhere, inevitably. This seems to he a simple case in which the discouraging entropic tendency to disarray and destruction of diversity is negated. This bas been apparent for the past 100 years, if one looked carefully a t simple models, and thought carefully. Yet it was not learned until a few years ago, when finally the insistence of nature forced it upon us. Why does this lag occur? Whence the resistance to drawing the inference from the observation? There seems to be a block, a mysterious difficulty in internalizing relationships, and in proclaiming consequences which are logical but elude us for long periods. It appears that chemistry does not develop in a linear fashion. Two observations are not like two points which determine a line, and they do not lead inevitably to a unique third point on the road to a solution. Instead for a long way along the road the stations retain a singular character, and logic may still lead from them along many alternative paths. Experience may help one avoid the dead-end paths, and encourage a bold stride down the fruitful way, but experience may also be very inhibiting for a long period. What appears to be fresh, daring vision is usually the result of much laborious thought, which may involve the slow discarding of earlier strongly held views. In the latter aspect of the process the inexperienced may have a big advantage. I learned another important lesson in my period at Polaroid Corporation, a lesson in human and institutional relations: that it was possible to work at a high level of attainment, while showing respect and consideration in interpersonal relations, indeed that i t was necessary to do so. It is possible to achieve greatly over an extended period within and by means of a complex, technical, institutional situation only by the establishment and maintenance of a sense of mutual respect. This atmosphere derives to a remarkable extent from the attitude of the chief officers of the institution to those about them, and thence from their behavior towards those about them. It is one case in which the trickle down principle is valid. It was probably the optimistic notion that one could solve any problem that allowed me to move on to Brandeis University. There I found a few students, some dis-
822 /Journal of Chemical Education
tinguished faculty, some old buildings, an enterprising President, and no research. There was curiosity, skepticism, and I think, respect when I asked to have utilities installed in my office so that I might start experiments. I became chairman of the School of Science and set out to attract faculty, who would be teachers and scholars, in four disciplines, biology, chemistry, physics and mathematics, and in limited areas within those disciplines. We should become proficient in a few contiguous areas, rather than offer instruction in many, and in these areas knowledge should be advanced. I held to the view that this limited institution should have as its goal to become not a good small college, but a good small university. I believed that the apparently grander goal was more readily attainable, since this would inspire greater effort and draw greater support. Scholarship might be defined relatively clearly, and excellence in it might be achieved, while less readily defined goals might remain elusive. Graduate degree programs, including one in chemistry, were introduced as soon as undergraduate degrees were granted for the first time. This increased the complexity of the operation, I became Dean of Faculty, and departmental structure and a Faculty Senate were established. A Faculty Handbook was written and subsequent events in the universities nation-wide indicated that such documents may be useful as guide and breakwater. I found the experience a maturing one, which left me with fewer illusions. I came to the realization of the reactive character of work. What one is, in terms of talents and values, may determine what one does, if the choice is available. But what one does, day in and day out, strongly affects what one is. It was a disquieting thought, and after a period I returned to learning and teaching and research in chemistry. Literature Cited Ill I21 IS1 (41 I51 (61
Cahen. S. G., and Sehneidei, A , J. Amer. C h e m S o e . 63,3382 11941). Cohen, S. G . . J . A m s r . C h e m Soc., 66.1935 119441. Cohen. S. G.. J.Amer. C h e m Soc., 61.17 (19451. Sachw, H..Re,.. 23, 1363 118901; 2.l'hus. Chrm.. 10,203 11892). Mohr, E.. J. Prakt. Chem.. 98.:115 119181. Kohlrausch. K. W. F.. Reirz. A. W.. and Stochmair. W.. 2. P h e . Chrm.. 832, 229 119W
(71 Haarel, 0.. Tfdwki.Kjemi. Berg". Met., 1.32 1194%). (81 Bart0n.D. H.R.E x p e r k t i n . 6. 31fi(19601. P.. sndcnhen. S . G . . J A m e r . C h s m Sac.. 78,M91(19~61. I91 AIBehui,
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