In this first subsection of the fifth chapter of Being as Communion, Zizioulas distinguishes two approaches to the idea of apostolicity, both of which can be traced to the New Testament.

The first approach sees the apostles as persons who are given a mission to fulfil, and

…in an approach inspired by the idea of mission, the apostles represent a link between Christ and the Church and form part of a historical process with a decisive and perhaps normative role to play. Thus the idea of mission and that of historical process go together in the New Testament and lead to a scheme of continuity in a linear movement: God sends Christ – Christ sends the apostles – the apostles transmit the message of Christ by establishing Churches and ministers. We may, therefore, call this approach “historical.” (173)

The second, eschatological, approach sees the apostles not so much as individuals who are sent, but rather as a college whose members are drawn together from the ends of the earth.

In this case the apostles’ relation both to Christ and to the Church is expressed in a way different from that of the historical approach. Here the apostles are not those who follow Christ but who surround Him. And they do not stand as a link between Christ and the Church in a historical process but are the foundations of the Church in a presence of the Kingdom of God here and now. (175)

Both of these approaches continued to exist in the post-apostolic Church. In I Clement we see an example of the first approach and this text has been influential in the development of the idea of apostolic succession. However, in the letters of Saint Ignatius of Antioch we see an example of the second approach in which

Continuity … is guaranteed and expressed not by way of succession from generation to generation and from individual to individual, but in and through the convocation of the Church in one place, i.e. through its eucharistic structure. It is a continuity of communities and Churches that constitutes and expresses apostolic succession in this approach. (177)

Thus the point that Zizioulas wants to make is that

in the very beginning of the Church’s consciousness of continuity with the apostles – and this applies both to the Eastern and to the Western Churches – there are hidden seeds of two approaches to this continuity, of an “historical” and an “eschatological” approach. (177-178)

He then proceeds to probe some of the implications of these two approaches.

Firstly, there is a difference in the understanding of continuity. The historical approach is concerned with succession or survival in time. Although this can be understood in different ways, it is based on a retrospective continuity.

The anamnetic function of the Church is employed here in a psychological way, and this leads to the creation of a consciousness of continuity with the past. The Church recalls a time called “apostolic”; whether she relates to it through various media or by way of copying as faithfully as possible this normative period, the fact remains that in this approach her apostolicity comes from the side of the past. (178)

In the eschatological approach, by contrast, apostolicity comes to the Church from the side of the future.

It is the anticipation of the end, the final nature of the Church that reveals her apostolic character. This anticipation should not be misunderstood as psychological; it is not a feeling of expectation and hope that is offered through it, but a real presence of the eschata here and now. “Now is the judgment of the world,” and now, this simple moment of the Johannine nu=n, all of history is consummated. The finality or ultimacy of things is what the eschatological approach to apostolicity brings forth. It is the Risen Christ that is related to apostolicity, i.e. the final and ultimate destiny of all that exists. (178-179)

Moreover, this has bearing on our understanding of Christology and Pneumatology and their relation to the apostolic origin of the Church. In the historical approach Christology is primary and both it and the notion of the apostolate a self-defined event which the Holy Spirit, who is sent by Christ, vivifies. He is the animator of a basically pre-conceived structure. However, in the eschatological approach, the Holy Spirit is the one who brings the eschata into history, confronting history with its consummation and changing linear historicity into a presence.

When the eschata visit us, the Church’s anamnesis acquires the eucharistic paradox which no historical consciousness can every comprehend, i.e. the memory of the future, as we find it in the anaphora of the Liturgy of St John Chrysostom: “Remember the cross, the resurrection, the ascension and the second coming, Thine own of Thine own we offer thee.” Unless the Church lets Pneumatology so condition Christology that the sequence of “yesterday-today-tomorrow” is transcended, she will not do full justice to Pneumatology; she will enslave the Spirit in a linear Heilsgeschichte. Yet the Spirit is “the Lord” who transcends linear history and turns historical continuity into a presence. (180)

Our ideas of apostolicity are therefore tied up with all of theology and

if the Church is to be truly apostolic, she must be both historically and eschatologically orientated; she must both transmit history and judge history by placing it in the light of the eschata. (181)

In the next subsection Zizioulas point towards a synthesis of these two approaches.