Many people feel that the making of value judgments is an important aspect of the work of science. This paper explores some of the arguments in support of the claim that scientific work requires individual and social values and raises significant moral questions. Discussed here are: (1) the constitutive value of science; (2) the ethics involved in scientific work; (3) the decisions and risks of hypothesis acceptance; (4) theory appraisal; and (5) the significance of science values. The final section considers the implication of the presence of values and norms in scientific activity for the objectivity of scientific results. (CW)