Styāna

StyÃÂna (Sanskrit; Tibetan phonetic: mukpa) or thÃÂ«na (Pali) is a Buddhist term that is translated as "sloth", "lethargy", "gloominess", etc. In the Mahayana tradition, styÃÂna is defined as a mental factor that causes the mind to be withdrawn, unclear, and unable to focus. ThÃÂ«na is defined as sluggishness or dullness of mind, characterized by a lack of driving power. In the Theravada tradition, thÃÂ«na is said to occur in conjunction with middha (torpor), which is defined as a morbid state that is characterized by unwieldiness, lack of energy, and opposition to wholesome activity. The two mental factors in conjunction are expressed as thÃÂ«na-middha (sloth-torpor).

StyÃÂna or thÃÂ«na is identified as:

One of the five hindrances to meditation practice (in combination with middha, i.e. as sloth-torpor)
One of the fourteen unwholesome mental factors within the Theravada Abhidharma teachings
Closely related to the Sanskrit term kausÃÂ«dya (spiritual sloth), that is identified as one of the twenty secondary unwholesome factors within the Mahayana Abhidharma teachings

Definitions

Theravada

Bhikkhu Bodhi explains:

The AtthasÃÂlinÃÂ« (II, Book I, Part IX, Chapter II, 255) states about sloth and torpor: Ã¢ÂÂAbsence of striving, difficulty through inability, is the meaning.Ã¢ÂÂ We then read the following definitions of sloth and torpor:

Nina van Gorkom explains:

Mahayana

The Abhidharma-samuccaya states:

What is gloominess' It is the way in which the mind cannot function properly and is associated with moha. Its function is to aid all basic and proximate emotions.

Mipham Rinpoche states:

Lethargy belongs to the category of delusion. It means to be withdrawn, mentally incapable, and unable to focus on an object because of heaviness of body and mind. It forms the support for the disturbing emotions.

Alexander Berzin explains:

Foggymindedness (rmugs-pa) is a part of naivety (moha). It is a heavy feeling of body and mind that makes the mind unclear, unserviceable, and incapable either of giving rise to a cognitive appearance of its object or of apprehending the object correctly. When the mind actually becomes unclear, due to foggymindedness, this is mental dullness (bying-ba).

References

Sources

Berzin, Alexander (2006), Primary Minds and the 51 Mental Factors
Bhikkhu Bodhi (2003), A Comprehensive Manual of Abhidhamma, Pariyatti Publishing
Guenther, Herbert V. & Leslie S. Kawamura (1975), Mind in Buddhist Psychology: A Translation of Ye-shes rgyal-mtshan's "The Necklace of Clear Understanding" Dharma Publishing. Kindle Edition.
Kunsang, Erik Pema (translator) (2004). Gateway to Knowledge, Vol. 1. North Atlantic Books.
Nina van Gorkom (2010), Cetasikas, Zolag