Final answer:
Disease had a profound impact on New World natives and Old World Europeans with different views on its causes and treatments. Nascher promoted geriatrics, advocating for diligent care for the elderly, while historical accounts reveal the native populations' vulnerability to European diseases, which hindered their resistance against invaders.
Step-by-step explanation:
The impact of disease on both New World natives and Old World Europeans was significant, with differing views on the causes and treatments of disease influencing both societies' medical practices. For instance, Nascher had a progressive view on disease, particularly concerning the elderly, and contested the dismissive attitude of his time toward geriatric care. He advocated for the prolongation of life and the relief of suffering through the medical field of geriatrics, outlining his views in his book Geriatrics: The Diseases of Old Age and Their Treatment. Meanwhile, sources like A Pest in the Land: New World Epidemics in a Global Perspective by Suzanne Austin Alchon provide insights into the cultural and medical perspectives of the Native Americans and the Old World, highlighting the devastating impact of disease on indigenous populations, especially due to their susceptibility to European diseases.
In the Old World, figures such as Hippocrates and Marcus Terentius Varro proposed natural and environmental causes for diseases, while the New World saw diseases affecting their ability to resist European invaders significantly.