Rather, the law must seek decisions that fall within the boundaries of scientifically sound knowledge and approximately reflect the scientific state of the art. This objective is sometimes difficult to achieve in practice. The most obvious reason is that most judges lack the scientific training that might facilitate the evaluation of scientific claims or the evaluation of expert witnesses who make such claims. They typically are generalists, dealing with cases that can vary widely in subject matter. Furthermore, science itself may be highly uncertain and controversial with respect to many of the matters that come before the courts.
Scientists often express considerable uncertainty about the dangers of a particular substance.
And their views may differ about many related questions that courts may have to answer. Many difficult legal cases fall within the heartland of this kind of scientific uncertainty. Finally, a court proceeding, such as a trial, is not simply a search for dispassionate truth. The law must be fair. In our country, it must always seek to protect basic human liberties.