From a famous couplet of 18-century poet Mirza Ghalib to the freely available pearls of wisdom on internet and widely-researched legal doctrines on mercy killing across the globe - the Supreme Court ruling on euthanasia refers to all of these.

"Marte hain aarzoo mein marne ki, Maut aati hai par nahin aati (One dies longing for death but death, despite being around, is elusive)," Justice Markandey Katju quoted Ghalib, while starting his 141-page judgement on euthanasia (mercy killing) plea for Aruna Ramachandra Shanbaug, a sexual assault victim lying in a vegetative state in Mumbai hospital for 37 years.

In a path-breaking ruling, the bench rejected a plea for mercy killing for Aruna and ruled that passive euthanasia, however, can be executed if the high court decides in its favour in case a plea is made to it.

"Euthanasia is one of the most perplexing issues which the courts and legislatures all over the world are facing today," he said in his ruling.

"This court, in this case, is facing the same issue, and we feel like a ship in an uncharted sea, seeking some guidance by the light thrown by the legislations and judicial pronouncements of foreign countries, as well as the submissions of learned counsels before us."

A voracious reader and a judicial philosopher in his own right, Justice Katju, who often quotes from the Upnishads, the Bhagwad Gita, the Quran in his judgements, has in this case the help of the internet to differentiate between passive and active euthanasia.