Is Fantasy a dream or an escape?

[HerenIstarion]

I've been reading Lewis' essays the other day, and lo! Here's what Tolkien once said to Lewis:

Stories of the sort I'm describing* are like that visit to the deck**. They cool us... Hence the uneasiness which they arouse in those who, for whatever reason, wish to keep us wholly imprisoned in the immediate conflict. That perhaps is why people are so ready with the charge of 'escape'. I never fully understood it till my friend Professor Tolkien asked me the very simple question, 'What class of men would you expect to be most preoccupied with, and most hostile to, the idea of escape?' and gave the obvious answer: jailers... those who brood much on the remote past or future, or stare long at the night sky, are less likely than others to be ardent or orthodox partisans

* i.e. Fantasy
** some pages prior to this sentence, Lewis gives an analogy of the quarrel of ship's stewards in the saloon, which occupies all minds to the extent all forget that besides puny politics adn management there is the sea and the sky outside and what is outside the ship matters much more than petty quarrels within her.

This particular passage comes from an essay On Science Fiction from the book named Of Other Worlds, my copy being reprint of Harvest Books 1975 edition, ISBN 0-15-602767-4. This collection deals with fairy tales/fantasy/criticism mainly and Lewis mentions Tolkein a lot, even quoting from On Fairy Stories to illustrate some points. But this instance of direct quoting I thought worthy of sharing here.