they don’t recognize the uniqueness of Judaism,
Of course they do. Don’t be motzi la’az like that. They just believe that there is what so be gained from the outside world as well.
and that Judaism is the only religion that carries with it the concept of “Deveikus”
That isn’t really true. Other religions also have a similar idea. We just believe that their way of getting there is, obviously, mistaken. But that’s neither here nor there.
This ‘Deveikus’ concept opens up a deep dimension in a person’s feelings, which only grows with each Torah learning and mitzvah which he subsequently does. This is the value which I claimed as central and exclusive to Chareidi philosophy.
“D’veikus” per se, as you refer to it, is a mystical concept, wihch your typical yeshiva bachur does not meet up with except in a couple of paragraphs of Mesilas Yesharim. In the yeshivas I’ve been to they didn’t talk about d’veikus that much, more about shleimus, and if anything, about “being davuk to the Torah,” I think that to say that “d’veikus” is the central chareidi philosophy is wholly incorrect. The truth is I think it’s a joke to say that there is a real “central philosophy” in the litvishe velt. Machshava isn’t central at all. As I once heard a litvishe Rosh Yeshiva say when there was a well known Machshava speaker in town and guys went to hear him – “You enjoyed it, yeh? Nu, but Teireh is the fleish and potatos!”