Alexander Fleming

The greatest discovery of all time was that of penicillin, and the greatest tragedy was that it was not discovered sooner.

It is not the discovery of a new substance that is important, but the discovery of a new principle.

The public thinks that I discovered penicillin in a flash of genius. It was nothing of the sort.

It is a curious thing that the most important discoveries are often made by accident.

I have often been asked if I regret not patenting penicillin. My answer is always the same: 'How could I patent the sun?'

The mold was there, I just happened to notice it.

It is not the size of the dog in the fight, it's the size of the fight in the dog.

I have no doubt that the future of medicine lies in the hands of the bacteriologist.

The world is full of wonders, but they are often hidden in plain sight.

It is a good thing to be lucky, but it is a better thing to be prepared.

The greatest satisfaction in life is to know that you have done something useful.

I have often been asked what I would do if I had to do it all over again. My answer is always the same: 'I would do it all over again, but I would try to be a bit tidier.'

The more you know, the more you realize you don't know.

It is not enough to discover, one must also apply.

I am not a prophet, but I can see the future of medicine.

I have never been a great believer in luck. I believe in hard work and perseverance.

It's a funny old world, and it's getting funnier all the time.

The greatest reward for a scientist is not money or fame, but the satisfaction of contributing to human knowledge.

I have always been a bit of a maverick, and I think that has helped me in my scientific career.

The future belongs to those who believe in the beauty of their dreams.