The progressive clarification of the details of the laws concerning membership of the Houses of Justice has been accompanied by a gradual implementation of their provisions. For example, based on the texts available to the believers at the time, membership of local Houses of Justice was initially confined to men. When the Master began to elaborate on the difference between the levels of this Institution, He clarified that the exclusion of women applied only to the Universal House of Justice. Thereafter, women became eligible for service as members of Local and National Spiritual Assemblies. Women in the West, who already enjoyed the benefits of education and opportunities for social involvement, participated in this form of service much sooner than, for instance, their Bahá'í sisters in Iran who were accorded this right only in 1954, "removing thereby the last remaining obstacle to the enjoyment of complete equality of rights in the conduct of the administrative affairs of the Persian Bahá'í Community". It is important to note that the timing of the introduction of the provisions called for by the interpretations of 'Abdu'l Baha and the Guardian in relation to the Local and National Spiritual Assemblies, rather than constituting a response to some external condition or pressure, was dictated by the principle of progressive implementation of the laws, as enjoined by Bahá'u'lláh Himself.
(The Universal House of Justice, from a letter dated 31 May 1988)