Alexander Fleming

It is not the strength of the body that counts, but the strength of the spirit.

The most important thing is to keep an open mind.

The greatest danger to our future is apathy.

I am not a genius. I am just a very curious person.

The greatest lesson I have learned is that there is always something new to learn.

The important thing is not to stop questioning. Curiosity has its own reason for existence.

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 enterprise, thought, and perception of an individual.

Penicillin was a chance discovery, but my whole scientific life had been a preparation for it.

I did not invent penicillin. Nature did that. I only discovered it by accident.

The unprepared mind cannot see the outstretched hand of opportunity.

There is no such thing as a pure culture. There is always a mixture.

The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug make them resistant.

The greatest possibility of evil in self-medication is the use of too small doses so that instead of clearing up infection, the microbes are educated to resist penicillin and a host of penicillin-fast organisms is bred out which can be passed to other individuals.

I have been trying to point out that in our lives chance may have an astonishing influence and, if I may offer advice to the young laboratory worker, it would be this—never neglect an extraordinary appearance or happening.

The popular name for it is 'penicillin'. The chemical name is something like that too.

For the birth of something new, there has to be a happening. Newton saw an apple fall; James Watt watched a kettle boil; Roentgen fogged some photographic plates. And these people knew enough to translate ordinary happenings into something new.

Discovery is not just seeing what everybody else has seen, but thinking what nobody else has thought.

In my first publication I might have claimed that I had come to the conclusion, as a result of serious study of the literature and deep thought, that valuable antibacterial substances were made by moulds and that I set out to investigate the problem. That would have been untrue and I preferred to tell the truth that penicillin started as a chance observation.

The initial discovery was made in a laboratory which was, by modern standards, poorly equipped.

A clean bench is the sign of a lazy microbiologist.