There's a nice essay on the novel here. It could be interesting to compare Musil's philosophy with Wittgenstein's. A couple of quotes:
By exercising great and manifold skill we manage to produce a dazzling deception by the aid of which we are capable of living alongside the most uncanny things and remaining perfectly calm by it. […] We are capable of living between one open chasm of the sky above our heads and one slightly camouflaged chasm of the sky beneath our feet, feeling ourselves as untroubled on the earth as in a room with the door locked.(That's Ulrich from the second volume of The Man Without Qualities.)
That's Musil himself. Both quotations taken from Achille C. Varzi's essay.Every work of art offers not merely an immediate experience but an experience that can never be completely repeated. […] The person dancing or listening, who yields himself to the moment of the music, the viewer, the person transported, is liberated from everything before and after […] This condition is never of long duration except in pathological form; it is a hypothetical borderline case, which one approaches only to fall back repeatedly into the normal condition, and precisely this distinguishes art from mysticism, that art never entirely loses its connection with the ordinary attitude. It seems, then, like a dependent condition, like a bridge arching away from solid ground as if it possessed a corresponding pier in the realm of the imaginary.