Tertullian — Against Marcion 2.5-6
I find that man was set up by God free — of his own decision and of his own power. I notice no greater image and likeness of God in him than this form of status.
For he was not stamped toward the one God by face and bodily lines — so varied in the human race — but in that substance he drew from God himself, that is the soul, marked toward God’s form, which pledges the freedom and power of his own decision.
The law God then set confirmed this status. A law would not be laid on someone who did not have the owed obedience to the law in his own power; nor would the threat of death be written against transgression if contempt of the law were not charged to man as freedom of decision.
So also in the later laws of the Creator you will find him setting before man good and evil, life and death.
[…]
So full freedom of decision was granted him toward either side, that as his own master he might steadily meet good by keeping it willingly and evil by avoiding it willingly — since a man set under God’s judgment had to make that judgment just by the deserts of his own free decision. Otherwise neither reward for good nor for evil could rightly be weighed out to someone who turned out good or evil by necessity, not by willing.
Latin
liberum et sui arbitrii et suae potestatis inuenio hominem a deo institutum, nullam magis imaginem et similitudinem dei in illo animaduertens quam eiusmodi status formam. neque enim facie et corporalibus lineis, tam uariis in genere humano, ad uniformem deum expressus est, sed in ea substantia, quam ab ipso deo traxit, id est anima, ad formam dei, spondentis et arbitrii sui libertatem et potestatem, signatus est. hunc statum eius confirmauit etiam ipsa lex tunc a deo posita. non enim poneretur lex ei, qui non haberet obsequium debitum legi in sua potestate, nec rursus comminatio mortis transgressioni adscriberetur, si non et contemptus legis in arbitrii libertatem homini deputaretur. sic et in posteris legibus creatoris inuenias proponentis ante hominem bonum et malum, uitam et mortem. […] tota ergo libertas arbitrii in utramque partem concessa est illi, ut sui dominus constanter occurreret et bono sponte seruando et malo sponte uitando, quoniam et alias positum hominem sub iudicio dei oportebat iustum illud efficere de arbitrii sui meritis, liberi scilicet. ceterum nec boni nec mali merces iure pensaretur ei, qui aut bonus aut malus necessitate fuisset inuentus, non uoluntate.