"The whole truth" versus "the admissible truth": an ethics dilemma for expert witnesses.

The expert witness testifies under oath to tell "the whole truth," yet certain aspects of the legal system itself make this ideal difficult or impossible. The authors present both a philosophical and a practical discussion of the challenges for the expert in attaining this goal. After review of oaths in general and truth-telling in particular, real-life examples are provided to examine the vicissitudes of the whole truth in court. Recommendations are provided for experts, to preserve the truth in the adversary system.