Is there a Santa Claus?

The brat asked me this last night. In all earnestness. Wondering where on earth he would hang his stocking. Given he has no stockings to start with and then wondered if simple socks would do. And how would gifts fit into a sock, only a small Hotwheels car or a small action figure could fit in. That too if Santa opened the giftwrapping. And the box. And how would Santa know what he already had and what he really really wanted. And would Santa get the orders confused with that of T who lived in the next wing, and really really wanted a Power Ranger Operation Overdrive Megazord vehicle. Which the brat doesnt want, because he wants the original Omnitrix from Ben 10 Battle of the Omnitrix, which will now make his life complete because he already has the growed up Ben 10 costuum thanks to Aunty Rads and all he needs is the original Omnitrix to be Ben 10. And some aliens. Maybe the help of some hair gel to get the exact look.
He's already been told by the cynics in his class, all of 6, that there is no Santa Claus. That the parents get the gifts. And are you stoopid, how can reindeers fly in the sky widoaud rockets under them? And how so many gifts for so many children can fit in one small sleigh. When did my little baby turn so sceptical. Mamma hung onto the concept of a Santa Claus till she hit adolescence, despite 'knowing' there was no jolly man in red, distributing largesse across the world on one single night, squeezing down chimneys without Harry Potteresque Floo powder. Mamma took heart from this, and is going to tell brat her version of it:

(Excerpt from The Sun, editorial, Yes Virginia, There is a Santa Claus.)

"Dear Editor--I am eight years old."Some of my little friends say there is no Santa Claus."Papa says, 'If you see it in The Sun, it's so.'"Please tell me the truth, is there a Santa Claus?
Virginia O'Hanlon115 W. 95th Street
Virginia, your little friends are wrong. They have been affected by the scepticism of a sceptical age. They do not believe except they see. They think that nothing can be which is not comprehensible by their little minds. All minds, Virginia, whether they be men's or children's are little. In this great universe of ours man is a mere insect, an ant, in his intellect, as compared with the boundless world about him, as measured by the intelligence capable of grasping the whole of truth and knowledge.
Yes, Virginia, there is a Santa Claus. He exists as certainly as love and generosity and devotion exist, and you know that they abound and give to your life its highest beauty and joy. Alas! how dreary would be the world if there were no Santa Claus! It would be as dreary as if there were no Virginias. There would be no child-like faith then, no poetry, no romance to make tolerable this existence. We should have no enjoyment, except in sense and sight. The eternal light with which childhood fills the world would be extinguished.
Not believe in Santa Claus! You might as well not believe in fairies! You might get your papa to hire men to watch in all the chimneys on Christmas eve to catch Santa Claus, but even if you did not see Santa Claus coming down, what would that prove? Nobody sees Santa Claus, but that is no sign that there is no Santa Claus. The most real things in the world are those that neither children nor men can see. Did you ever see fairies dancing on the lawn? Of course not, but that's no proof that they are not there. Nobody can conceive or imagine all the wonders there are unseen and unseeable in the world.
You tear apart the baby's rattle and see what makes the noise inside, but there is a veil covering the unseen world which not the strongest man, nor even the united strength of all the strongest men that ever lived, could tear apart. Only faith, fancy, poetry, love, romance, can push aside that curtain and view and picture the supernal beauty and glory beyond. Is it all real? Ah, Virginia, in all this world there is nothing else real and abiding.
No Santa Claus! Thank God! he lives, and he lives forever. A thousand years from now, Virginia, nay, ten times ten thousand years from now, he will continue to make glad the heart of childhood.

How do you explain Santa Claus to your children?