The word sesshin is made up of two Chinese ideograms with multiple meanings. The first is setsu (literally "to link together"), which means "unification", but also "reception", "touch" and "continuation". The other ideogram, shin (literally 'mind'), refers to the perception of the mind in its various aspects, both individual and universal. It can therefore be said that sesshin is an opportunity to unite these two: the universal mind (called the great mind, often explained metaphorically by analogy with, for example, God, the Buddha, the universe, etc.) with the 'ordinary' mind of the practitioner (the small mind, made up of thoughts, sensations, emotions and various personal conditionings).

During zazen, which is the basis of the sesshinAs the practice continues, the individual's awareness grows and his or her actions become attuned to the rhythm of all things, leading to a natural attunement with reality as it is. As the practice continues, the individual's awareness increases and his or her actions become attuned to the rhythm of all things, leading to a natural harmonisation with reality as it is. The ideogram setsu also means "to know", "to regulate" and "to control" - and this is precisely what the practice of sesshin. The programme of activities for a sesshin is not random, and all the activities are designed to 'tune' the practitioner's mind to existing reality, both external and his or her own mental reality.