Concepts of 20th century physics—quantum mechanics, theory of relativity, doctrine of indeterminacy—have had a profound effect on historiography. They provided scientific metaphors of relativity and uncertainty for distrusting written history. Involvement of the observer with the observed—so prominent in physical science both at the level of the atom and that of outer space—has been extrapolated to history writing as a bias factor. Since no historian can use all available data, he must select those which to him seem important, and this selection in itself is in the nature of interpretation influenced by individual bias, which is compounded when the selected information is finally to interpretive analysis.
In the narrower context of medical patient-history taking, the objectivity of the observer has long been suspect. How objective is the physician who asks leading questions slanted so as to confirm a suspicion generated by a superficial impression, a preconceived idea, or a recently