The paper is dedicated to the centennial of Professor Lev Markovich Vekker (1918—2001), who was one of the most significant and profound theoreticians in Russian psychology of the second half of the XX century. Vekker was a student of B.G. Ananyev, so he carried on the St. Petersburg — Leningrad scholarly traditions. He was known for his encyclopedic knowledge and academic courage that enabled him to formulate and resolve the grand scientific task of finding underpinnings for basic principles of integrated theory of mental processes. Within this theory, he described the consistency of these basic principles across mental processes of various levels of development and complexity. The revealing of general regularities of such processes was combined with the analysis of their specificity. Vekker believed that this was the only way to systematize the avalanche-like growth of empirical data and defeat a "thousand-headed hydra of empirism". We believe that underestimation of Vekker's theoretical heritage may carry some dramatic consequences for the development of modern psychology. The paper describes the interpretative and prognostic potential of the basic principles of Vekker's theoretical framework, and how useful this framework can be for resolving the most essential problems of psychology, including origins of mind, localization of mental imagery, structure of intelligence and mechanisms of its development, mental time as a basis for memory and attention, as well as various practical and differential-diagnostics tasks.