Our Knowledge Can Only Be Finite, While

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.

We Hate The Very Idea That Our Own Ideas May Be Mistaken, So We Cling Dogmatically To Our Conjectures.

The Attempt To Make Heaven On Earth Invariably Produces Hell.

Science Is Perhaps The Only Human Activity In Which Errors Are Systematically Criticized And, In Time, Corrected.

Psychologism Is, I Believe, Correct Only In So Far As It Insists Upon What May Be Called 'methodological Individualism' As Opposed To 'methodological Collectivism'; It Rightly Insists That The 'behaviour' And The 'actions' Of Collectives, Such As States Or Social Groups, Must Be Reduced To The Behaviour And To The Actions Of Human Individuals. But The Belief That The Choice Of Such An Individualist Method Implies The Choice Of A Psychological Method Is Mistaken.