Forgetfulness of all earthly things, desire for heavenly things, immunity from all intensity and all disquiet, from all cares and all worries, from all trouble and all effort, the plenitude of work without agitation. The delights of feeling without the work of thought. The ravishments of ecstasy without medication. In a word, the happiness of pure spirituality in the heart of the world and amidst the tumult of the senses. It is no more than the gladness of an hour, a minute, an instant. But this instant, this minute of piety spreads its sweetness over our months and our years.
So excellent and accurate is this description of the mystical experience that I cannot doubt that the above entry records an actual experience of Joubert's.
Light. It is a fire that does not burn. (Notebooks, 21)
Just as the eyes are the most spiritual of the bodily organs, light is the most spiritual of physical phenomena. And there is no light like the lambent light of the desert. The low humidity, the sparseness of vegetation that even in its arboreal forms hugs the ground, the long, long vistas that draw the eye out to shimmering buttes and mesas -- all of these contribute to the illusion that the light is alive. This light does not consume, like fire, but allows things to appear. It licks, like flames, but does not incinerate. ('Lambent' from Latin lambere, to lick.)
Light as phenomenon, as appearance, is not something merely physical. It is as much mind as matter. Without its appearance to mind it would not be what it, phenomenologically, is. But the light that allows rocks and coyotes to appear, itself appears. This seen light is seen within a clearing, eine Lichtung, which is light in a transcendental sense. But this transcendental light in whose light both illuminated objects and physical light appear, points back to the onto-theological Source of this transcendental light.
Augustine claims to have glimpsed this eternal Source Light upon entering into his "inmost being." Entering there, he saw with his soul's eye, "above that same eye of my soul, above my mind, an unchangeable light." He continues:
It was not this common light, plain to all flesh, nor a greater light of the same kind . . . Not such was that light, but different, far different from all other lights. Nor was it above my mind, as oil is above water, or sky above earth. It was above my mind, because it made me, and I was beneath it, because I was made by it. He who knows the truth, knows that light, and he who knows it knows eternity. (Confessions, Book VII, Chapter 10)
'Light,' then, has several senses. There is the light of physics, which is but a theoretical posit. There is physical light as we see it, whether in the form of illuminated things such as yonder mesa, or sources of illumination such as the sun, or the lambent space between them. There is the transcendental light of mind without which nothing at all would appear. There is, above this transcendental light, its Source.
One could characterize a materialist as one who is blind to the light, except in the first of the four senses lately mentioned.