To set out underway, to enter the between, is to enter this spiritual twilight of blueness. It is “spiritual” insofar as Heidegger follows Trakl in understanding spirit as a flame capable of offering inviting warmth at a hearth as well as burning everything to ashes in conflagration. Spirit as flame is never wholly one or the other of these, it is always in between. The loss of oneself by entry into the between occurs at “twilight” (Dämmerung), the crepuscular transition of the day. It is not simply the end of the day, but also the dawn of morning; “morning, too, has its twilight [dämmert]”. Twilight is always between the end and the beginning. Lastly, the between is a spiritual twilight of “blueness” insofar as blue is the color of twilight, of the time that is neither day nor night. Blue is the color of the trace, of what remains light in the dark and dark within light. As Heidegger puts it, “the brightness sheltered in the dark is blueness”.
P. 108From The Fourfold, Andrew J. Mitchell.