This concept has been attributed to St Augustine of Hippo as part of his refutation of the Donatist sect. He was strongly influenced by the Platonist belief that true reality is invisible and that, if the visible reflects the invisible, it does so only partially and imperfectly (see Theory of Forms). Others question whether Augustine really held to some form of an "invisible true Church" concept. Later Pietism took this one step further with its ecclesiolae in ecclesia. This encyclical rejected two extreme views of the Church: