The Fact That Knowledge Endlessly Recedes As

Man Can Learn Nothing Unless He Proceeds From The Known To The Unknown.

It Is Impossible To Devise An Experiment Without A Preconceived Idea; Devising An Experiment, We Said, Is Putting A Question; We Never Conceive A Question Without An Idea Which Invites An Answer. I Consider It, Therefore, An Absolute Principle That Experiments Must Always Be Devised In View Of A Preconceived Idea, No Matter If The Idea Be Not Very Clear Nor Very Well Defined.

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.

Feeling Alone Guides The Mind.

Real Science Exists, Then, Only From The Moment When A Phenomenon Is Accurately Defined As To Its Nature And Rigorously Determined In Relation To Its Material Conditions, That Is, When Its Law Is Known. Before That, We Have Only Groping And Empiricism.