²⁹This idea, reduction of desires leading to an empty mind, shows how the question of causality regarding emptiness of mind and happiness/suffering is complex. (See also footnote 33 in Chapter 9.) We started this section by pointing out that emptying the mind by meditation often has the effect of making people feel more joyful (as reported by many meditators), and this is consistent with the idea that the ensuing reduction of simulation should logically reduce suffering. Thus, emptying the mind was seen as an intervention that causally reduces suffering. In contrast, the idea that reducing desires reduces (especially wandering) thoughts is in line with some classical Buddhist authors who seem to claim that the emptiness of mind is mainly an effect of mental development, not a cause of happiness (Williams, 2008b, p. 55). In such thinking, reducing desires reduces frustration as discussed in Chapter 14, and an empty mind is just a side-effect. Meanwhile, the discussion on the experiential cognitive style just given could probably be interpreted based on either causal direction; either an experiential style makes the mind empty, or emptying the mind leads to a more experiential style; or perhaps both are effects of the reduction of desires or some similar cause.