Sakshi bhava, the witness attitude, is widely taught in contemporary yoga and Vedanta influenced meditation as a practical technique, observing thoughts and feelings as they arise without immediately identifying with or reacting to them, a method that gives the ancient philosophical concept a directly applicable contemplative use.
Where Samkhya and Advaita part company is in where this practice is understood to end: Samkhya's dualism treats the witness as a permanently separate, real entity, purusha, whose recognition of its own difference from prakriti is itself the goal and the final state of liberation, kaivalya, isolation. Advaita treats the witness stance as an intermediate teaching, useful and even necessary at a certain stage, but ultimately to be seen through rather than settled into, since the tradition's final claim is that witness and witnessed, like waking and dreaming, are appearances within a single non dual reality rather than two permanently distinct principles. This difference over the witness's final status is one of the clearest technical markers separating Samkhya's classical dualism from Advaita's non dualism, two positions that otherwise share a great deal of vocabulary and practice in common.