There Is No History, Only Histories.

No Particular Theory May Ever Be Regarded As Absolutely Certain.... No Scientific Theory Is Sacrosanct.

Definitions.... Are Never Really Needed, And Rarely Of Any Use

Simple Statements Are To Be Prized More Highly Than Less Simple Ones Because They Tell Us More; Because Their Empirical Content Is Greater; And Because They Are Better Testable.

Genuine Philosophical Problems Are Always Rooted Outside Philosophy And They Die If These Roots Decay.

The Growth Of Our Knowledge Is The Result Of A Process Closely Resembling What Darwin Called 'natural Selection'; That Is, The Natural Selection Of Hypotheses: Our Knowledge Consists, At Every Moment, Of Those Hypotheses Which Have Shown Their (comparative) Fitness By Surviving So Far In Their Struggle For Existence, A Competitive Struggle Which Eliminates Those Hypotheses Which Are Unfit.