Carl Jung, 'The Psychological Types':
"Feeling is the extraverted attitude that is oriented by objective data. I.e the object is an indispensable determinant of the kind of feeling. It agrees with objective values. If one has always known feeling as a subjective fact, the nature of extraverted feeling will not be immediately understood, since it has freed itself as fully as possible from the subjective factor, and has, instead, become wholly subordinated to the influence of the object.
In precisely the same way as extraverted thinking strives to rid itself of subjective influences, extraverted feeling has to undergo as certain process of differentiation. The valuations resulting from the act of feeling either corresponds directly with objective values or at least chime in with certain traditional and generally known standards of value. Without this feeling, for instance, a beautiful and harmonius sociability would be unthinkable. So far extraverted feeling is just as benificient and rationally effective as extraverted thinking."