Medicinal science involves the study of pharmaca, especially of chemicals used in medicine as therapeutic and occasionally as prophylactic agents. It is based on combinations of experimental biology and chemistry and physics applied to the understanding of pathologies and restoring normal conditions in animal cells and tissues. The widest areas contributing to medicinal science are medicinal chemistry, biochemistry and pathology applied to metabolic aberrations, pharmacology, microbiology and virology, endocrinology and immunology. Many medical specialties funnel information into medicinal science and vice versa where pharmacotherapeutic treatment is involved. It would be a great advantage if unified concepts could be found to tie all these activities together. In physics and chemistry, the trend toward such generalizations is making progress. Biology and behavioral sciences are approaching the stage at which many of their phenomena are becoming classifiable as chemical and physical manifestations. But unified explanations in biology run into difficulties through refined visual observations and instrumental measurements. As we advance toward visualization of macromolecules by electron microscopy, X-ray diffractometry and other spectroscopic methods, we witness a centrifugal expansion of what had been thought to be ultimate biological entities only a few years ago. Where ‘animate’ matter and macromolecules meet we recognize the growing importance of molecular aggregation and polymerization.