Otto Toeplitz (1881 - 1940) was a leading scholar in linear algebra and functional analysis and coauthor of The Enjoyment of Mathematics.
There is much that all of us can learn about the teaching of calculus from this book....It is above all a delightful and entertaining introduction to mathematical problems that have inspired the creation of calculus. Read it for the sheer enjoyment of well-crafted explanations. Read it to learn something new. - from the Foreword by David Bressoud