In Hinduism, Ananda Samapatti is the stabilizing the mind by making one of the sense organs the object of concentration. Samapatti is defined by Sage Patanjali (Yogasutra I.41) as a state of stability of mind in which there is perfect unity with an object due to purity and clarity resulting from removal of impurities like fluctuations.
Patanjali groups all objects of concentration into three
categories, namely, grahita, that which comprehends, and grahya, that which is
comprehended.
Grahya consists of all the objects of experience, the five
elements, namely, earth, fire, water, air, and vacuum, and their tanmatras
(five subtle forms). Grahana includes thirteen indriyas (sense organs). Ten of
them are external (five cognitive organs and five motor organs), and three
internal – manas (mind), ahamkara or asmita (ego feeling) – and buddhi
(intellect). Grahita means the self which is the principle of comprehension.
Samapatti, in which one of the sense organs is an object of
concentration or the stability of the mind (adhara or alambana), is called Ananda
samapatti (Yogasutra I.17). Ananda means blissfulness; the mind is filled with
joy in its unity with a sense organ.
The unity of the mind with the object in samapatti is called
tadrupata (like salt dissolved in water), or tadakarata (like water assuming
the shape of a vessel), or tadanjanta (like a crystal showing the color of an
object in its vicinity vividly and intensely). Such a harmonious, complete, and
vivid unity of the mind with an object is an outstanding mark of samapatti. Its
essential prerequisite is freedom from mind-fluctuations or a state of
ksinavritti.