From the exposition of facts… we infer that bloodletting has had very little influence
All [knowledge] comes from experience, it is true, but experience is nothing if it does not form collections of similar facts. Now, to make collections is to count.
Between the one who counts the facts, grouped according to their resemblance, in order to know what to believe regarding the value of therapeutic agents and him who does not count but always says "more or less frequent," there is the difference between truth and error, between something that is clear and truly scientific and something that is vague and without value—for what place is there in Science for that which is vague?