Ratio of order; theology directs fallen man; know thyself and know God
The reason of order requires that, after we have explained how great and of what kind that highest good is which is both man's most absolute happiness and his perfection, we treat here of man, the citizen of God's kingdom, because he himself is the one to whom by this discipline, built and founded upon the divinely revealed Word, we show the way by which he may decline the extreme misery into which he fell when the bond of conjunction with God was broken, and may return to the highest beatitude, righteousness, and life of God.
For since sacred Theology, dealing with the divine kingdom, does not inform both God the King and man the subject at once — as politics, dealing with a human commonwealth, informs both the prince and the subject citizen — but directs only man fallen into misery toward recovering beatitude; therefore we call its subject especially man, insofar as he is to be subjected to God his King, united to Him, and forever kept, as was declared in Book I, chapters 1 and 4-7. For in this the kingdom of God chiefly consists (Luke 17:21; Matthew 13:23; Luke 8:11; Romans 14:17-18).
We will therefore not teach everything about man that can be known of him, but only those things which declare his character in any way in order toward the kingdom of God and eternal life. And so this part of Theology will hand on that divine saying Know thyself, and thence the other no less necessary: Know GOD, your Creator and Redeemer.
Latin
RATIO ordinis postulat, ut, posteaquam explicavimus, quantum & quale sit summum illud bonum, quod hominis & absolutissima felicitas & perfectio est, hic de homine, cive regni Dei, tractemus, quia is ipse est, cui hac disciplina super verbum divinitus revelatum exstructa & fundata viam ostendimus, qua extremam miseriam, in quam rupto cum Deo conjunctionis vinculo incidit, declinet, & ad summam beatitudinem, justitiam & vitam Dei reveniat. Nam quia S. Theologia, de regno divino agens, non & Deum regem simul informat, & subditum hominem: sicut politica de rep. humana agens & principem & subditum civem: sed solum hominem in miseriam lapsum ad beatitudinem recuperandam dirigit; ideo subjectum illius praecipue dicimus hominem, quatenus Deo regi suo, subjiciendus, uniendus & aeternum servandus est, ut lib. 1. cap. 1, 4-7. declaratum est. In hoc enim regnum Dei potissimum est, Luc. 17.21, Matth. 13.23, Luc. 8.11. Rom. 14.17-18. Non igitur de homine docebimus omnia, quae de eo sciri possunt, sed ea duntaxat, quae illius indolem in ordine ad regnum Dei & vitam aeternam quoquo modo declarant. Atque ita haec pars Theologiae tradet divinum illud gnothi seauton, Nosce teipsum, indeque alterum non minus necessarium: gnothi Theon, Nosce DEUM, creatorem, redemtoremque tuum.