We have always known that heedless self-interest was bad morals; we know now that it is bad economics.

Franklin Delano Roosevelt (1882–1945) American lawyer, politician, statesman, US President (1933–1945)

Speech (1937-01-20), Inaugural Address, Washington, D.C.
    (Source)

(Source (Audio)). Regarding the Stock Market Crash and ensuing Great Depression.