Father Boris Bobrinskoy continues his discussion of Tradition in the ninth chapter of The Compassion of the Father by distinguishing between the “horizontality” of what is transmitted in the Church and the “verticality” of the work of the Holy Spirit. In the work of Saint Irenaeus of Lyons we find the explication of Tradition as something whose content is one and the same and cannot be added to nor diminished, but which is also not impoverished by human transmission “because the Holy Spirit always makes us contemporaries to the history of salvation.” (159) By expounding on the doctrine of apostolic succession, Irenaeus showed the continuity of transmission in the Church. However,

the living apostolic Tradition is, above all, a transmission. In a transmission, there is, indeed, a double movement. First, there is a reception through the ages, through the centuries: we receive, and what we receive becomes a part of ourselves, or rather, we become that which we receive; we assimilate one another, identify ourselves with the content of the Tradition. Next, there is a transmission through us, of what has been received in a chain unbroken to the end of the ages. In this respect, it is appropriate to make another distinction between Tradition as a living transmission and Tradition as the content of the faith. (160)

This living transmission is the work of the Holy Spirit and it is fundamentally relational.

the Tradition is the work of the Spirit who penetrates into the content of the deposit of the transmitted faith, and who enlightens the one who receives it. This transmission is always of the order of a relationship and of personal progress, of a dialogue from heart to heart, from mouth to ear, of an interiorization. More than a phenomenon, we are faced with a true mystery: spiritual fatherhood.

For the deposit of faith to be transmitted unchanged and unchangeable from generation to generation, to retain its integrity, fullness, and simplicity – such as it has been uttered, carried out, and realized in Jesus Christ – the Holy Spirit must act and allow those who have received it and are in agreement with this life and message faithfully to transmit it. In this sense, the concept of spiritual fatherhood, of spiritual begetting, most appropriately expresses what constitutes the nerve, axis, and spinal cord of this living reality of the Tradition – irreducible to the external transmission of a truth or a philosophy. (160)

While the concept of fatherhood is a broad one, and while various forms of fatherhood exist in the Church, it is fundamentally connected to the transmission of life itself.

Transmission becomes a genuine experience. What is transmitted is fire. As long as truths remain on the intellectual, cerebral plane, there will be no chance of transmission because they are aloof and cold. Only that which burns can illumine and kindle the core of a being. (160)

Thus,

This fatherhood is an essential act of the Holy Spirit, in which the two dimensions meet: “horizontality” and “verticality”; “horizontality” because it is uninterrupted since the first centuries until today and will remain so until the end of time; “verticality” because, beyond all human mediations and pedagogies, God is and remains our only Father, Christ our only Lord, and the Holy Spirit our only physician in the growth of the faith. (161)