INTRODUCTORY COMMENTS 



C. B. VAN NiEL 



Hopkins Marine Station of Stanford University, 

 Pacific Grove, California 



On introducing the session on photosynthesis in this symposium, 

 I may be permitted a few introductory remarks. It is not uncommon 

 to find that scientists, like artists, have a habit of defending what 

 they like to do best as the best possible approach to it. There is 

 considerable justification for this because it implies a certain amount 

 of pleasure in one's work. On the other hand, it has also been de- 

 fended in a beautiful manner in that little treatise of Bronowski 

 on "Science and Human Values", where he paraphrases Coleridge 

 who spoke of poetry, by saying that science is the search for vinity 

 in the wild variety of oiu' experiences. Now this emphasizes two 

 different things. It emphasizes unity and it also emphasizes variety. 

 While there is every reason to emphasize unity perhaps more, this 

 is not a good justification for eliminating variety. For that reason, 

 I would like to state that in my opinion the notion that we can 

 understand life if and when we understand energy transfer is per- 

 haps too restricted. Energy transfer is no doubt one of the funda- 

 mental aspects, but so are other things. Life is characterized perhaps 

 more than anything else by organization. Organization in its very 

 simplest form is the organization of elementary particles into mole- 

 cules. It is this aspect that has for several years been in the hands 

 of biochemists who have studied enzyme-controlled reactions, and 

 it should be admitted that on the basis of that approach a great deal 

 has been learned. The importance of that aspect for photosynthesis 

 can perhaps be introduced by saying that about a decade ago the 

 first attempts were made to reconstitute the enzymatic mechanism 

 of the photosynthetic process, approached independently by Vishniac 

 and Ochoa, by Tolmach, and by Arnon and Whatley. From this 

 starting point Calvin, Benson, Bassham and their collaborators have 

 taken off and in a period of ten years have amassed a quantity of 

 beautiful evidence that has given us a very considerable insight 

 into the details of the manner in which carbon dioxide is converted 



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