Professor Murray Gell-Mann is one of the most influential and brilliant scientists of the twentieth century. His work on symmetries, including the invention of the "quark," in the 1950s and early 1960s provided the foundation for much of modern particle physics. His contribution to the field earned him the Nobel Prize for Physics in 1969. This book is a collection of research articles by eminent scientists written especially to celebrate Gell-Mann's 60th birthday, in September 1989. The main body of contributions is concerned with theoretical particle physics and its applications to cosmology, and includes papers by such notables as J. Hartle, E. Witten, H. Fritzsch, T.D. Lee, I.M. Singer, V. Telegdi, and some personal remarks by A. Salam and M.L. Goldberger.