Some doors I designed, some I bump into and feel like a product of my own imagination.
Some I could recognize, some I could only vaguely fathom, but still somehow they were mine.
If the doors of perception were
cleansed everything would appear to
man as it is, infinite.
William Blake, The Marriage of Heaven and Hell, 1790
A threshold is a gate, a door, it defines a boundary where something ends, begins or changes.
A threshold is what you step across when you enter a room, but first and foremost it takes you from one place into another, it is the point of access where something starts to happen and become different.