Almost no germ is ...

Almost no germ is unconditionally dangerous to man; its disease-producing ability depends upon the body's resistance.
 Hans Selye

Quotes from the same author

Unlock your natural drives by doing what you enjoy.
 Hans Selye
I doubt that Fleming could have obtained a grant for the discovery of penicillin on that basis [a requirement for highly detailed research plans] because he could not have said, 'I propose to have an accident in a culture so that it will be spoiled by a mould falling on it, and I propose to recognize the possibility of extracting an antibiotic from this mould.'
 Hans Selye
Even after the greatest defeats, the depressing thought of being a failure is best combated by taking stock of all your past achievements.
 Hans Selye