Harmonious Mental Equilibrium (samma samadhi)
This is homeostasis, or the return to the original purity and tranquility of mind, which has been lost due to the emotional reaction to stimulation of the senses in the form attraction and repulsion. This state of equilibrium consists of five parts:
1. Inference (vitakka)
2. Inquiry (vicara)
3. Rapture of mind (piti)
4. Comfort of body (sukha)