Variability is the law of ...

Variability is the law of life, and as no two faces are the same, so no two bodies are alike, and no two individuals react alike and behave alike under the abnormal conditions which we know as disease.
 William Osler

Quotes from the same author

Nature, the great Moloch, which exacts a frightful tax of human blood, sparing neither young nor old; taking the child from the cradle, the mother from her babe, and the father from the family.
 William Osler
Varicose veins are the result of an improper selection of grandparents.
 William Osler
To it, more than to anything else, I owe whatever success I have had - to this power of settling down to the day's work and trying to do it to the best of one's ability, and letting the future take care of itself.
 William Osler
Live neither in the past nor in the future, but let each day's work absorb your entire energies, and satisfy your widest ambition.
 William Osler
Personally, I do not see in Canada it would be a feasible thing if any Ministry organized taking over both the Health and the Disease of the entire community... even in the most favourable circumstances... there would be that absence of competition and that sense of independence... I do not believe it would be good for the profession or good for the Public.
 William Osler