“The laws of the unconditioned (which we will call the vertical) are inherently contradictory to the laws of the conditioned (which we will call the horizontal). The horizontal and the vertical are perpendicular to one another, but do bisect at one location, the present. The vertical ‘is,’ and that is about all one can say about it. The vertical requires nothing to be added because nothing is missing. It is intrinsic to all things, but makes no demands upon them. It cannot be perceived because it is within perception itself. There is no way to it, and there is no way out of it.
The horizontal world of conditioning is a time-driven, labor-intensive, multidimensional universe, extending far beyond its junction with the vertical. To the left, as far as the mind can see, is time past, and to the right is the infinite expanse of time future. Since future and past have no reality outside thought, the horizontal universe is both composed and driven by concepts. This means it has no true authenticity other than the validity we give an idea or image. The only uncontested point is the here and now, at the place where it bisects with the vertical universe. The person on the horizontal rarely acknowledges the touch of the vertical; there is little interest in a timeless universe.
From the horizontal perspective, the present is a moment between time past and time future, a deprived moment on its way to some other time. The future holds the hope and potential, the present holds the pain of who I am now, so the momentum is to move as quickly as possible away from the present of what I am, in the direction of who I will become.
The vertical perspective of the here and now is very different. Since the moment is not being squeezed between the rock of the past and the hard place of the future, it is open and expansive. In fact, it is infinite and total, encompassing all things including thoughts about past and future, because all thoughts are occurring here and now. So the vertical universe actually encompasses the horizontal universe. Noting could possibly escape the moment or ever be outside it, so the vertical universe is always abiding and never moves. Things move within it, but it never moves. Moment after moment we are taking birth in the vertical universe; the problem is we think we are in the horizontal. Occasionally we pause sufficiently to see the intersection of these dimensions and not merely think our way past them. It may be in a moment of wonder, mystery, beauty, or a moment too precious to deny.”
Smith R. "Stepping out of self-deception. The Buddha's liberating teaching of no-self." Shambhala, Boston, 2010.