For while the theory of Ecclesiastical Development has a _direct_ relation only to the question in regard to the Rule of Faith, it has also an _indirect_ or _collateral_ relation to the truths of Natural as well as of Revealed Religion; and this relation demands for it, especially in the existing state of theological speculation, the earnest attention of all who are concerned for the maintenance even of the simplest and most elementary articles of Divine truth. The most elaborate and systematic exposition of this theory is exhibited in the "Essay on the Development of Christian Doctrine, by JOHN HENRY NEWMAN;" an Essay primarily directed to the discussion of the points of difference between the Popish and the Protestant Churches, but which will be found to have an important bearing, also, on some doctrines which are common to both, and especially on the fundamental articles of Natural Religion itself. It is thus stated by Mr. Newman:[91] "That the increase and expansion of the Christian Creed and Ritual, and the variations which have attended the process in the case of individual writers and churches, are the necessary attendants on any philosophy or polity which takes possession of the intellect and heart, and has had any wide or extended dominion; that, from the nature of the human mind, time is necessary for the full comprehension and perfection of great ideas; and that the highest and most wonderful truths, though communicated to the world once for all by inspired teachers, could not be comprehended all at once by the recipients, but, as received and transmitted by minds not inspired, and through media which were human, have required only the longer time and deeper thought for their full elucidation. This may be called _the Theory of Developments_."