The powers of the mind should be concentrated and the mind turned back upon itself; as the darkest places reveal their secrets before the penetrating rays of the sun, so will the concentrated mind penetrate its own innermost secrets.
Swami VivekanandaThe body and mind are continually changing, and are, in fact, only names of series of changeful phenomena, like rivers whose waters are in a constant state of flux, yet presenting the appearance of unbroken streams. Every particle in this body is continually changing; no one has the same body for many minutes together, and yet we think of it as the same body.
Swami Vivekananda