Four mental engagements

The nine ways of resting the mind, or stages of shamatha practice can be condensed into four mental engagements (Wyl. yid la byed pa bzhi):

1. Tightly Focused Engagement – relates to the first two stages of resting the mind
2. Interrupted Engagement – this occurs from stage three to stage seven, when one is still susceptible to the obstacles of dullness and agitation and is therefore unable to abide for a long time
3. Uninterrupted Engagement – at stage eight one is able to remain unaffected by the obstacles of dullness and agitation without too much exertion
4. Effortless Engagement – at the ninth stage one is able to maintain the practice effortlessly