#### by Alan D. Weinstein

I have known Shoshichi Kobayashi since the 1960′s, when I started here as a graduate student. I have been a faculty member since 1969, and it is partly thanks to Sho that I am still here. He was chair when I had an offer from Caltech in the late 1970′s. He very effectively convinced me to forsake sunny Southern California and return to Berkeley, on attractive terms which he negotiated on my behalf. Part of the arrangement was for me to serve as his Vice-Chair for Faculty Appointments for a year upon my return. This may not sound like much of a prize to many of you who have done that kind of administrative job recently. But, in fact, Sho did himself much of the work himself which other chairs delegated to their vice-chairs, so I was very lucky.

I’m very glad that things worked out as they did; among other things, it gave Margo and me many opportunities to enjoy the company of Sho and his wife, whom we always knew by her very appropriate English name of Grace.

Sho has left a most impressive mathematical legacy in the form of a roster of 35 Ph.D. students, a long list of contributions to differential geometry, and many influential monographs.

Perhaps the most well-known mathematical object bearing his name is the “Kobayashi pseudometric,” which he introduced in 1967. Despite a name which makes it sound like something fake, this is a real measure of distance which quickly became in Sho’s hands, and remains throughout the mathematical world, an essential tool for the study of mappings between and within complex manifolds.

These are spaces, some of whose directions are parameterized by “imaginary numbers”, but that is not where the “pseudo” comes from. The “pseudo” refers to the fact that, in some spaces, two different points could have zero distance between them. Sho identified the absence of this undesirable property as one which characterized certain “good” spaces which he called “hyperbolic” and which are known as “Kobayashi hyperbolic.”

Sho’s work remained concentrated in the area of complex geometry, where he made a string of fundamental contributions throughout a career of over fifty years, but he worked in other areas of differential geometry as well. One of my own papers was a variation on a theme he created in a paper on positively curved manifolds.

Sho was a master of mathematical communication. He even wrote a paper called “How to write a mathematical paper (in English).” (It was written in Japanese.) More important, his books, especially the two-volume “Foundations of Differential Geometry” with Katsumi Nomizu, have taught differential geometry and complex geometry to generations of students and other researchers.

Sho was my personal agent for “opening Japan to the West.” Through his collaborator Takushiro Ochiai, I was invited to visit the University of Tokyo in the Spring of 1987, and Japan has become for me and Margo one of our two favorite destinations (along with France, where Sho himself made his first foreign mathematical visit). We have gone back many many times and even, a couple of times, benefited from the collection of equipment which he and Grace accumulated for the guest apartments of Keio University.

We share the grief of the Kobayashi family, especially Grace, Mei, and Sumi, whom we have long known, as well as other members whom we met just today. We are glad that Sho’s passing was a peaceful one of the kind we all hope for, after a long and fulfilling life, but we will also miss very much his generous friendship, his sense of humor, and the wonderful smile to which Hisashi referred earlier this morning. Fortunately, Sho lives on in the form of his magnificent mathematical legacy and our memories of a wonderful man.