Revised edition of a survey of chemistry from the point of view of symmetry, presenting many examples from chemistry and other fields in order to emphasize the unifying nature of the concept of symmetry. After the introduction, the simplest symmetries are presented using chemical and nonchemical examples. Molecular geometry is then discussed in qualitative terms. Group-theoretical methods are applied in an introductory manner to the symmetries of molecular vibrations, electronic structure, and chemical reactions. These chapters are followed by a descriptive discussion of space-group symmetries, concluding with the symmetry of crystals.