Instead, however, of the deduction of the supreme principle of pure practical reason, that is, the explanation of the possibility of such a knowledge a priori, the utmost we were able to do was to show that if we saw the possibility of the freedom of an efficient cause, we should also see not merely the possibility, but even the necessity, of the moral law as the supreme practical law of rational beings, to whom we attribute freedom of causality of their will; because both concepts are so inseparably united that we might define practical freedom as independence of the will on anything but the moral law.
Arrazoimen praktiko hutsaren printzipio gorenaren dedukzioaren ordez, hau da, apriorizko ezagutza halakoaren ahalgarritasunaren argipenaren ordez, ezingo litzateke hau baino adierazi ezen, kausa eragile baten askatasunaren ahalgarritasuna ulertuko balitz, lege moralaren ahalgarritasuna ez ezik haren beharrezkotasuna ere ulertuko litzatekeela euren nahimenaren kausalitatearen askatasuna egozten diegun zerizan arrazoidunen lege praktiko goren gisa, bi adigaiak hain modu bereiztezinean daudelako lotuta, non askatasun praktikoa nahimenak lege morala ez beste guztitik duen beregaintasun gisa definitu ahal izango baikenu.