Theory Not Only Formulates What We Know

Special Emphasis Should Be Laid On This Intimate Interrelation Of General Statements About Empirical Fact With The Logical Elements And Structure Of Theoretical Systems.

A Theoretical System Does Not Merely State Facts Which Have Been Observed And That Logically Deducible Relations To Other Facts Which Have Also Been Observed.

It Is That Of Increasing Knowledge Of Empirical Fact, Intimately Combined With Changing Interpretations Of This Body Of Fact - Hence Changing General Statements About It - And, Not Least, A Changing A Structure Of The Theoretical System.

If There Are Four Equations And Only Three Variables, And No One Of The Equations Is Derivable From The Others By Algebraic Manipulation Then There Is Another Variable Missing.

The Functions Of The Family In A Highly Differentiated Society Are Not To Be Interpreted As Functions Directly On Behalf Of The Society, But On Behalf Of Personality.