This is the Stoic doctrine.  “Stoicorum quidem facilis conclusio est; qui cum finem bonorum esse senserint, congruere naturæ, cumque ea convenienter vivere.”  cf. Cic., De Fin. iii. 7, 26, and De Nat. D. i. 14, and Hor., Ep., i. x. 12.  “Vivere naturæ si convenienter oportet.”  So the Stoics’ main rule of life is ὁμολογουμένως τῇ φύσει ζῆν.  But with Basil this apparent disregard of the doctrine of original sin and the need of grace for redemption must be understood in the light of the catholic doctrine that sin is the corruption of human nature (cf. Art. ix. of Original or Birth Sin), which nature, though corrupt and prone to evil, retains capacities for good.  But these capacities do need grace and training.  cf. Basil’s Homily on Ps. xlv. 166.  “What is said about the Saviour had a double sense on account of the nature of the Godhead and the Economy of the incarnation.  So, looking to the humanity of God, it is said ‘thou hast loved righteousness and hated iniquity,’ instead of saying ‘the rest of men by toil and discipline and careful attention mostly attain a disposition towards good and an aversion from vice.  But thou hast a kind of natural relationship to good and alienation from iniquity.’  And so to us, if we will, it is not hard to acquire a love of righteousness and a hatred of iniquity.”  i.e. In Christ, redeemed humanity loves good, and all men ‘naturally’ do need toil and discipline.  The heredity of sin is recognised by Basil.  (e.g. in Hom. in Famen. 7.)  Man fell from grace given, and must return to it.  (Serm. Ascet. in init.)  It must always be remembered that questions of original sin, the will, and grace never had the same importance in the Greek as they had in the Latin church.  cf. Dr. Travers Smith on St. Basil (c. ix. p. 108) and Böhringer (Das Vierte Jahrhundert. Basil, p. 102) who remarks:  Wenn er auch noch von einer “Wieder herstellung des freien Willens, den wir zu brauchbaren Gefässen für den Herrn und zu jedem guten Werke fähig Werden” (De spir. sanct. 18) spricht, so hat er dies doch nirgends begründet, obschon er bei der Besprechung der Folgen des Falls zuweilen sich äussert, es sei der Mensch der von dem Schöpfer erhaltenen Freiheit beraubt worden.  Im Allgemeinen setzt er den freien Willen auch nach dem Fall im Menschen so gut wieder Voraus, wie vor dem Fall, so dass jene Aeusserungen kaum mehr als den Werth einer Redensart haben.  Im Ganzen eriunert seine Darstellung wieder an diejenige des Athanasius, dessen Einfluss Man nicht verkennen kann.