The profiles overlap in time and place. Manuscripts remained active after print, spoken and household knowledge continued outside institutions, and new instruments still depended on trained bodies, paper records, and interpretation.
Approximately 1650–1550 BCE: the Edwin Smith Papyrus and Ebers Papyrus preserve Egyptian compilations through particular scribal copies. Their physical rolls support dating and textual analysis, but neither names an original author or reveals the whole range of healing in ancient Egypt.
Fifth century BCE to the early second millennium CE: works now treated as classics—including the Hippocratic Oath, Charaka Samhita, Sushruta Samhita, and Huangdi Neijing—survive through layered textual traditions. A date assigned to a surviving recension is not automatically the date of every passage, theory, or practice within it.
About 1000–1543: the instrument drawings in Al-Tasrif, Ibn Sina's Canon of Medicine, and Vesalius's Fabrica show knowledge changing through manuscript copying, commentary, translation, illustration, and print. Circulation was collaborative: authorship alone does not explain the labour of scribes, translators, artists, block cutters, printers, teachers, and readers.
1603–1858: the London Bills of Mortality made recurring urban counts available in print; De Motu Cordis combined anatomical argument with experiment; and the publications of Jenner, Snow, and Nightingale organised cases, interviews, tables, maps, and diagrams into public claims. These sources document persuasion as well as observation, and their British concentration should not stand for medicine everywhere.
1819–1953: the stethoscope, ether inhaler, radiograph, culture plate, and newborn score mediated hearing, drug delivery, vision, laboratory observation, and clinical comparison. None was self-interpreting, and familiar replicas or images can conceal changing designs, users, risks, and claims of priority.
1910–1979: the Flexner Report, Nuremberg Code, WHO Constitution, and Belmont Report made reform, rights, and responsibility matters of institutional text. Their authority, jurisdiction, implementation, exclusions, and later reputation differ; listing principles is not evidence that institutions observed them.