1 The following are the transactions which they narrate as having occurred outside of the Pleroma: The enthymesis of that Sophia who dwells above, which they also term Achamoth, being removed from the Pleroma, together with her passion, they relate to have, as a matter of course, become violently excited in those places of darkness and vacuity [to which she had been banished]. For she was excluded from light and the Pleroma, and was without form or figure, like an untimely birth, because she had received nothing [from a male parent].
But the Christ dwelling on high took pity upon her; and having extended himself through and beyond Stauros, he imparted a figure to her, but merely as respected substance, and not so as to convey intelligence. Having effected this, he withdrew his influence, and returned, leaving Achamoth to herself, in order that she, becoming sensible of her suffering as being severed from the Pleroma, might be influenced by the desire of better things, while she possessed in the meantime a kind of odour of immortality left in her by Christ and the Holy Spirit.
Wherefore also she is called by two names— Sophia after her father (for Sophia is spoken of as being her father), and Holy Spirit from that Spirit who is along with Christ. Having then obtained a form, along with intelligence, and being immediately deserted by that Logos who had been invisibly present with her— that is, by Christ — she strained herself to discover that light which had forsaken her, but could not effect her purpose, inasmuch as she was prevented by Horos. And as Horos thus obstructed her further progress, he exclaimed, Iao, whence, they say, this name Iao derived its origin.
And when she could not pass by Horos on account of that passion in which she had been involved, and because she alone had been left without, she then resigned herself to every sort of that manifold and varied state of passion to which she was subject; and thus she suffered grief on the one hand because she had not obtained the object of her desire, and fear on the other hand, lest life itself should fail her, as light had already done, while, in addition, she was in the greatest perplexity.
All these feelings were associated with ignorance. And this ignorance of hers was not like that of her mother, the first Sophia, an Æon, due to degeneracy by means of passion, but to an [innate] opposition [of nature to knowledge]. Moreover, another kind of passion fell upon her (Achamoth), namely, that of desiring to return to him who gave her life.
Source: Adversus haereses (New Advent)