Sooth is the Old English cognate of the Norse seiðr. It is spellcraft — the act of manifesting something in material reality through intentionality. In its broadest sense, every act of free will is sooth: the bringing of Heaven into Hell, of idea into matter, of intention into the world.

In Tianmu, sooth is distinguished by the realm from which it is wielded. Heaven-sooth and Hell-sooth each carry a blind spot — the unconscious limitation inherent in operating from one extreme. When consciousness acts from pure purpose, it is blind to desire; when it acts from pure craving, it is blind to clarity. In either case, the opposite force works unseen: pleasure creates pain, and pain creates pleasure, through the simple way opposites interact.

Midland-sooth lacks this blind spot. Because the middle realm is the meeting of both forces in full awareness, sooth wielded from Midland operates with a clarity that neither extreme can match. This is the practical basis for Tianmu's emphasis on cultivating middle-realm awareness.

The most important form of sooth in Tianmu is Ghostsooth — deity yoga, the practice of channelling and becoming a Ghost or force. The methods and forms through which sooth is practised are collectively called Weaving.