The article presents a review of the ideas and works of corresponding member of the USSR Academy of Sciences A. V. Stepanov, one of the founders of the theory of strength and plasticity of solids, during his creative period from 1930 through 1972. The work by A. V. Stepanov and his school covers many problems, starting with the study of crystal-damage processes, the mechanism of crystal plastic deformation, and ending with the control of crystallization processes and the obtaining of complex-shaped articles directly from the melt. In the theoretical field, Stepanov has not only advanced ideas concerning the mechanical properties of crystalline materials, but formulated also general laws governing the failure of solids, including crystals, oriented polymers, fibrous materials (lumber, composites), and biological and geological structures.