“How fortunate we didn't have these animal tests in the 1940s, for penicillin would probably not have been granted a licence, and possibly the whole field of antibiotics might never have been realised.”

— Reported in Dennis V. Parke, "Clinical Pharmacokinetics in Drug Safety Evaluation," in ATLA: Alternatives To Laboratory Animals, vol. 22, no. 3, May/June 1994, p. 208.; The context is: "the present approach to drug safety evaluation, based on experimental animal studies, is known to be of questionable scientific veracity and has never been satisfactorily validated as an appropriate surrogate system for man. My former teacher, Sir Alexander Fleming, in his late years, chided me, saying …"

“When I woke up just after dawn on September 28, 1928, I certainly didn’t plan to revolutionize all medicine by discovering the world’s first antibiotic, or bacteria killer, ... But I guess that was exactly what I did.”

“It is the lone worker who makes the first advance in a subject: the details may be worked out by a team, but the prime idea is due to the enterprise, thought, and perception of an individual.”