Sense-impression is a mental, not a physical, event. It is sixfold, as being conditioned either by one of the five physical senses or by the mind. This sixfold sense impression is the chief condition for the corresponding six kinds of feeling born of contact through the five physical senses and of mind-contact. The feeling that arises from contact with visual forms, sounds, odours and tastes is always a neutral feeling. But bodily impressions such as touch or pressure can cause either pleasant or unpleasant feelings.
Mental impressions can cause gladness, sadness or neutral indifferent feeling.
In other words, every conscious experience has a feeling-tone, pleasant, painful or neutral, the latter being also a distinct quality in its own right. The subsequent emotional, practical, moral or spiritual values attached to any particular feeling are determined by the associated mental factors belonging to the aggregate of mental formations. Since feeling, in its primary state, simply registers the impact of the object, in itself it is quite devoid of any emotional bias. Only when volitional evaluations are admitted will there appear emotions such as desire and love, aversion and hate, anxiety and fear, as well as distorting views. But these admixtures need not arise, as the emotions are not inseparable parts of the respective feelings.