Shri Siddharameshwar Maharaj from his one book "Golden Day"

   "The ancient Rishis in India first studied the material science but when they could not find the Real happiness therein, they progressed in the study of mental science. Here they made many wonderful discoveries, such as reading the minds of others, knowing things and events happening at a great distance, making one’s own form invisible to others, entering into another’s body, leaving his own, curing diseases both mental and physical by rechanting Mantras and moving through the sky and attained many other supernatural powers (siddhis); but ultimately they having found that these powers would not help them in the attainment of the Real and Eternal Happiness, directed their attention to know and realise the Soul. In this, they attained perfect Spiritual Content – they attained supreme felicity. Here they experienced unexcelled and boundless joy and happiness and in this state every one of them ejaculated “Blessed am I!”