True Science Teaches Us To Doubt And,

If I Had To Define Life In A Single Phrase, I Should Clearly Express My Thought Of Throwing Into Relief One Characteristic Which, In My Opinion, Sharply Differentiates Biological Science. I Should Say: Life Is Creation.

Even Mistaken Hypotheses And Theories Are Of Use In Leading To Discoveries. This Remark Is True In All The Sciences. The Alchemists Founded Chemistry By Pursuing Chimerical Problems And Theories Which Are False. In Physical Science, Which Is More Advanced Than Biology, We Might Still Cite Men Of Science Who Make Great Discoveries By Relying On False Theories.

Feeling Alone Guides The Mind.

In The Philosophic Sense, Observation Shows And Experiment Teaches.

The Great Experimental Principle, Then, Is Doubt, That Philosophic Doubt Which Leaves To The Mind Its Freedom And Initiative, And From Which The Virtues Most Valuable To Investigators In Physiology And Medicine Are Derived.