Belt

Scientific theories are never "e;true or "e;false"e;; they are "e;good"e; or "e;bad"e; in various degrees, and the criterion is one of usefulness-predictability and manipulation to (seeming) advantage. Theories are often discarded, simply because evidence may be insufficient for one, where it seems to sustain another-or where another can account for observed phenomena more simply. Take Lamarck's theories on the effect of environment on heredity; so far, the evidence seems to put this in the "e;bad"e; classification. But if certain experiments could be made....