Uncertainty and Measurements
THE CUSTOM has been to introduce students to the uncertainty principle by way of well-chosen empirical examples, and such is doubtless the proper heuristic procedure for making the principle's acquaintance and for learning to work with it. The novel discovery of uncertainty is indeed fraught with great pragmatic consequences, most of which display the unregenerate air of factualness and specificity that attaches to matters of observation and not to philosophic principles. Understandably, therefore, the physicist has at times behaved like the proud and somewhat embarrassed owner of a new and strange toy; he has taken delight in inviting his friends to admire it and in watching the philosopher's astonishment as he turned the switch and made it go. But the knowledge thus conveyed is not tantamount to understanding. Above all it tends to make the uncertainty principle appear like a proscription of certain experimental procedures or at best as a thesis of limited measurability, when in fact it is a basic innovation in our way of representing reality.
The inductive approach via selected experiments has historical importance because it is the psychological avenue which led Heisenberg to the discovery of the principle. Yet it may be said without disrespect for the facts of history that there comes a time when the necessity for organizing knowledge suggests an alternative approach, a logical approach from the side of basic axioms. Only when this is conjoined with the inductive story will the whole picture emerge, only then will the atmosphere of dogmatism which surrounds the principle be finally dispersed. For the philosopher knows that physicists have failed to be convincing, and have often even failed to make sense when explaining