Tekne was the old magic of the Nonmen, using the energy of unraveled souls to power their alteration of the world. Practitioners of Tekne draw this power into themselves not through expression of pure thought like anagogic sorcerers or through concentration on metaphor like gnostic wizards, but by transforming their souls into empty vessels. Those who perform Tekne must be able to remove desire and emotion from their minds, to make their own soul appear as an invisible gap in the weave so the energy released by a frayed soul naturally settles in the weave of the voided soul.
This magic required the sacrifice of living creatures, and usually a connection to the Walking Gods, but at the height of the Nonmen it was capable of creating works of magic unseen in the modern world. The Tekne was used to stitch instructions into machines, and combined with the Nonmen’s ability to create wondrous alloys due, formed into precise shapes that modern craftsmen cannot replicate, the Tekne allowed the Nonmen to create wondrous factories and automatons. Practitioners of Tekne are also able to reanimate dead creatures and enslave them, though these creatures, called Fvetala, have to constantly consume the souls of other creatures to remain animated.
Modern practitioners of Tekne are considered blasphemers in most parts of the world, as it requires living sacrifice, and to access the most powerful magic the sacrifice of sentient creatures. Most modern Tekne mages are bound to a Vestige to access the power of unraveled souls, though there are some who instead draw from the Anathem, and there is even rumor that some Gnostic wizards have developed ways to use Tekne.
There have been some reports of certain Sellspell colleges that will deploy illegal Tekne mages for a high cost, though currently this is considered hearsay. It is known that in same isolated areas of human lands practitioners find refuge of Nonmen ruins to practice their craft, and can easily carve out fiefdoms with reanimated Fvetala servants.