This chapter describes the neuroscience underlying our emotional lives, emphasising Jaak Panksepp’s work with emotional systems and levels of emotional control in the brain. Affect is primary in both body and brain. Core emotions are triggered deep in the brain, become subject to learnt habits at higher levels, and come into awareness in the cortex. Emotional arousal may be within our window of affective tolerance, or outside it in states of hyper-arousal and very low arousal. Therapy must be affective as well as cognitive so that cycles of arousal are completed. Working with the felt sense enables client and therapist to explore the implicit world of the right brain-body ensemble.