A practical jurisconsult (jurisperitus), or a professional lawyer, is one who is skilled in the knowledge of positive external laws, and who can apply them to cases that may occur in experience. Such practical knowledge of positive right, and law, may be regarded as belonging to jurisprudence (jurisprudentia) in the original sense of the term. But the theoretical knowledge of right and law in principle, as distinguished from positive laws and empirical cases, belongs to the pure science of right (jurisscientia).
Recognizing that ethical issues raised by the rapid advances in science and their technological applications should be examined with due respect to the dignity of the human person and universal respect for, and observance of, human rights and fundamental freedoms,
I have tried in this book to distinguish clearly two kinds of question, which moral philosophers have always professed to answer, but which, as I have tried to shew, they have almost always confused both with one another and with other questions. These two questions may be expressed, the first in the form: What kind of things ought to exist for their own sakes? the second in the form: What kind of actions ought we to perform?