The Buddha sometimes summarised in brief what he had explained in detail elsewhere (M.III,223). When summarising the various psychological states that assist in the apprehending of reality, he identified seven main ones and called them the Seven Limbs of Enlightenment (satta bojjhanga). These are mindfulness (sati), investigation of mental phenomena (dhammavicaya), energy (viriya), joy (pãti), tranquillity (passaddhi), concentration (samàdhi) and equanimity (upekkhà).
Mindfulness allows us to notice objects of reality and when we make an effort to scrutinize and explore their features we begin to see their changeable, inadequate and impersonal nature. Joy adds wings to our spiritual aspiration so that it does not become just a constant struggle, and tranquillity helps us keep our balance in the face of the various ups and downs we will inevitably encounter during our journey. Concentration keeps attention and energy focused so that our interest does not wane and we do not get sidetracked. Finally, equanimity quietens disruptive thoughts and emotions thus making the mind clear and meditation easier (D.II,79).