Pathology as defined by Welch1 is "the science, as distinguished from the practice, of medicine. In a narrower and more restricted sense pathology is a study of the structural alterations produced by the disease, as revealed at postmortem examinations and during surgical operations. Pathologic anatomy is a study of these alterations, but the symptoms and the activities of the body resulting from these morbid changes belong also to pathology."
"Nobody can busy himself continually with anatomy without noticing the changes that disease produces in the body" (Virchow2). The ancient concept that disease is something general, an essence which affects the organism as a whole, was completely shattered by Morgagni, who in the seventy-ninth year of his life published a condensation of a life's work in five volumes under the title "De sedibus et causis morborum per anatomen indagatis," which means "the seats and causes of disease as revealed
THE CHANGING CONCEPTS IN PATHOLOGY. JAMA. 1942;120(5):375-376. doi:10.1001/jama.1942.02830400049016