The Bar of Ireland is the representative body for barristers who are members of the Law Library in Ireland. The Irish Bar aims to provide its clients with a high level of expertise in all areas of law and skilled advocacy (pleading a case) by people of integrity and independence. The Irish legal system is based on the common law, which originated in England. This type of system attaches great significance to judge-made law. A decision in one case is legally binding on all subsequent cases with similar facts unless it is reversed by a higher court or on appeal. Other sources of law in Ireland include the Constitution, Acts of the Oireachtas (statutes) and the law of the European Communities. Under the Irish justice system, court hearings in contested cases are conducted in an adversarial manner. This means that each side presents its case and seeks to challenge that of its opponents through the evidence of its own witnesses, cross-examination and legal argument.