Plotinos: Complete Works, v. 1 In Chronological Order,...

9. All things therefore, which result either from a choice by the soul, or from exterior circumstances, are "necessary," or determined by a cause. Could anything, indeed, be found outside of these causes? If we gather into one glance all the causes we admit, we find the principles that produce everything, provided we count, amidst external causes, the influence exercised by the course of the stars. When a soul makes a decision, and carries it out because she is impelled thereto by external things, and yields to a blind impulse, we should not consider her determination and action to be free. The soul is not free when, perverting herself, she does not make decisions which direct her in the straight path. On the contrary, when she follows her own guide, pure and impassible reason, her determination is really voluntary, free and independent, and the deed she performs is really her own work, and not the consequence of an exterior impulse; she derives it from her inner power, her pure being, from the primary and sovereign principle which directs her, being deceived by no ignorance, nor vanquished by the power of appetites; for when the appetites invade the soul, and subdue her, they drag her with them by their violence, and she is rather "passive" than "active" in what she does.