The force drawn from the True Source that drives the universe and turns the Wheel of Time. It is divided into two halves: saidin (the male half) and saidar (the female half), which work simultaneously with and against each other. Only men can channel saidin and only women can channel saidar, though men and women working together are far more powerful than either alone. After the Dark One's counterstrike during the sealing of the Bore, saidin was tainted, causing any man who channelled it to go mad. The taint was cleansed by Rand al'Thor using the Choedan Kal.