ENFormation and definition of the Christian identity begins in the Letters of the Apostles, but it was more a response to the internal processes evolving in the community (a discussion on Jesus' authentic teaching, relations with Judaising trends, the status of heads and leaders of local communities, and the like). Construction of external restrictions and links forming a coherent whole began only in the second century. Aristides (the second half of the second century) was one of yhe first – and the first better extant –Christian thinkers that attempted a definition of the place of the Christian both historically and in the real present. Aristides' strategy is not only of delimination but also that of connections: his philosophical perspective is based on the Middle Platonism and the spreading cult of "God Most High", while the critique of the pagan religious absorbs its elements that are found not only in the Bible but in the Roman culture of that period as well. On the other hand, Aristides stresses the originality of the Christian lifestyle and ethics thus pointing to the fundamental vector of the dissociation from the surrounding culture.