CRITICISM OF INCLUDING THE CONCEPT OF DANGEROUSNESS IN LEGAL SYSTEMS HAS TAKEN THREE FORMS: THAT THE COMMONSENSE MEANING OF THE TERM IS TOO VAGUE AND AMBIGUOUS TO PERMIT THE PROMULGATION OF A SPECIFIC LEGAL DEFINITION; THAT LEGAL DEFINITIONS OF THE TERM HAVE BEEN RARE, CIRCULAR, MISGUIDED, OR IRRELEVANT; AND THAT ATTEMPTS TO PREDICT DANGEROUSNESS HAVE FAILED AND, FOR VARIOUS METHODOLOGICAL AND THEORETICAL REASONS, MUST NECESSARILY FAIL. DANGEROUSNESS CLEARLY DEFIES SIMPLE DEFINITION AND PREDICTION. SOME SCHOLARS HAVE SUGGESTED THAT, BECAUSE SITUATIONAL AND CONTEXTUAL VARIABLES PRECLUDE PREDICTION OF DANGEROUSNESS, RESEARCH AIMED AT SUCH PREDICTIONS SHOULD BE DISCONTINUED. NEVERTHELESS, THE PUBLIC STILL WISHES TO BE PROTECTED, MODEL PENAL CODES CONTINUE TO USE THE CONCEPT OF DANGEROUSNESS, AND CLINICIANS AND RESEARCHERS STILL FEEL THEY CAN AMELIORATE A SERIOUS SOCIAL PROBLEM BY PREDICTING DANGEROUSNESS. A COMPROMISE BETWEEN THESE OPPOSING VIEWS SEEMS DESIRABLE FROM THE PERSPECTIVES OF BOTH RESEARCH PLANNING AND LEGISLATIVE REFORM. PREDICTION RESEARCH MUST MEET THE REQUIREMENTS OF SOUND DESIGN, AND CAUTION MUST BE OBSERVED IN APPLYING ANY RESULT FROM PREDICTION RESEARCH. A REASONABLE APPROACH TO LEGISLATIVE REFORM MIGHT BE TO ENACT LAWS WHICH ALLOW FOR A SPECIAL CATEGORY OF DANGEROUS OFFENDERS BUT WHICH ALSO HAVE BUILT-IN SAFEGUARDS AGAINST THE ABUSE OF CIVIL LIBERTIES IN THE NAME OF PUBLIC PROTECTION OR NATIONAL SECURITY. SUCH LEGISLATION IS EXEMPLIFIED IN THE SCOTTISH COUNCIL ON CRIME'S RECOMMENDATION FOR THE ESTABLISHMENT OF A PUBLIC PROTECTION ORDER. THE SCOTTISH LEGISLATION DELINEATES PROCEDURES FOR SINGLING OUT VIOLENCE-PRONE OFFENDERS AND FOR GUARDING AGAINST UNWARRANTED DETENTION. A LIST OF REFERENCES IS INCLUDED. (LKM)