Early ethical investing was based on religious teaching. Jewish law dating to Biblical times includes the responsibility of owners to prevent immediate and potential harm, while Islamic teaching (609-632CE) has become the source for modern Shariah-compliant investment standards. Historically, several religions have included bans on the practice of lending money for interest. This is usually prohibited in Islamic finance but was also banned in the medieval Christian tradition.
Western ethical investing tradition has religious roots, notably among the Methodists and Quakers. More recent developments have been in response to the Vietnam War (the 1960s), concerns about nuclear issues (Three Mile Island 1979 and Chernobyl 1986), South African apartheid 1985-1993, global warming, biodiversity, and plastic pollution.
This article outlines some of the background leading to the modern conception of ethical or sustainable investing.
Q G Rayer (2019), The roots of ethical investing, DISCUS, available at http://discus.org.uk/the-roots-of-ethical-investing/, 5 pages, 19 September 2019.