The first and last principle of sacred theology is authentic and self-attesting

III. Among these principles one stands first and last; another hangs from that first principle and is ranked beneath it.

The distinction matters most under the Smyrnaean, Pergamene, Thyatiran, and above all the Sardian church-condition in which we now live. The Ephesian condition still had one principle alone — the written Word of God (Acts 28:25). Augustine praised that same character under the Pergamene state: Let us use the liberty to which the Lord has called us. As for those men whose praise we dare not equal, whose writings we refuse to set beside many Scriptures, whose genius we love, whose speech delights us, whose charity we admire, and whose martyrdoms we revere — whatever they thought otherwise, we must not receive it as canonical. We do them no injury when we mark off any saying or writing of theirs from the canonical authority of the divine Scriptures.

IV. Sacred theology's first and last principle is the one that, once granted, lets every other dogma of faith be deduced, while it itself is not deduced directly from any other — and therefore deserves to be called authentic and autopiston, self-attesting.

We name it first and last because Christian theological discourse cannot go beyond it without sliding into an infinite regress or a circle, and both paths are vicious. The proof runs in six steps. (1) Whatever is known is either a principle or a conclusion; philosophy already teaches that. In theology's dogmas concerning divine and eternal life, just as in other disciplines, we move from one point to another and prove one claim by arguing from another. (2) Those proofs and conclusions must halt in something first that is not itself proved from elsewhere — otherwise they circle or stretch to infinity, both of them faults. (3) First here means first for the Christian person's knowledge. (4) We are not requiring the principles of being and the principles of knowing to be identical everywhere; theology's own character often refuses that identity. God is author and principle of being for the whole creation. Yet our question is how it becomes established for us that God created all things. (5) Still more: the question is less how the point might be proved to this or that hearer, and more how it stands firm for the Christian — and on what he, who neither spins in a circle nor rushes on like a madman into infinity, is finally founded insofar as he is and is called a Christian. (6) Because we are asking for a principle ordered to our cognition, and for one from which further claims can be deduced by discourse, what we seek is plainly the complex principle that Aphorism 2 already named an axiom: an examined, proposed, authentic, autopiston principle.