Udayanācārya was a tenth-century Indian philosopher; his Nyayakusumanjali argues for the existence of Īśvara, who is cause, orderer, and sustainer of the world, the source of language, moral law, and rational thought, and the one who governs the workings of karma. I've come across a number of different versions of the legend of Udayana and the Buddhist, and have combined them.
Mighty of mind was great Udayana,
mighty in reason's ways;
his thought searched out the higher things
like hound that leaps and bays.
From lowest thing to holy God
in breadth and width and height
he walked on reason's highways
with reasons ever right.
Never wrong was great Udayana.
His inference was sure
and traveled straight like arrow-flight
and always would endure.
He was a great debater;
he could bring the point to close,
and the God-denying Buddhists
he held as his foes of foes.
Before the king of Mithila
he debated a Buddhist long.
His words were clear. His subtleties
and arguments were strong,
and at the end the Buddhist,
though for debate he had renown,
in defeat went to the highest cliff
and cast his body down:
ashamed of having been so wrong,
ashamed of his guilt and pride,
ashamed of having doubted God,
he leaped from the cliff and died.
Repenting, the great Udayana
went down to the temple-place
and before the God whom he had proved
he knelt and bowed his face.
The God gave not a whisper.
The silence was cool and cold,
and, anguished, great Udayana
spoke out in anger bold.
"My life has been a service,"
he said, "to lead minds to you,
and to the God-deniers,
I showed that you were true.
Why, then, are you silent?
My existence comes from yours,
but by my proof and reasons
your name with men endures."
Then a dream came to Udayana.
The God spoke the word, "Unclean,"
and a storm rose through the temple
and shook the temple-screen.
"You may argue, O Udayana,
and your arguments are sure,
but this is also true of God:
the God is wholly pure.
Let us take a proof, Udayana;
I will give it in a tale,
and by my proof know that proof
may, impure, come to fail.
A philosopher like Udayana
when Brahman and Buddhist fought
led them to the mountain
and gave them the proof they sought.
Down he threw the Brahman.
'There is a God,' the Brahman said,
and set down like a downy feather,
unscratched in limb and head.
Again he threw the Buddhist,
who said to the wind that sighed,
'There is no God, all things must end,'
and, ending, the Buddhist died.
It was a certain proving,
in a way that none could hide,
with only one objection:
that the Buddhist monk had died.
And from the sun of heaven
the fire of judgment fell
and cast impure philosopher
into deepest pits of hell.
God is most pure, Udayana,
the greatest eminence of holy life,
and shuns the bloody-handed
and the stirrer-up of strife.
Unfit are you, great Udayana,
though the truth may crown your head,
for though you spoke the truth of God,
by you man's blood is shed.
You have argued with godlike splendor
and your fellow men have awed;
your word of truth was light to man,
but darkness to the God."