Such realization challenges our normal perception of the opaqueness and solidity of forms. When we perceive a rock we do not only see or touch a form. We see a totally opaque shape, and touch a solid and substantial object. By realizing the absolute nature of the rock—by perceiving the form of the rock while simultaneously recognizing its final ontological mode—the rock seems to lose both opaqueness and solidity. Loss of opaqueness does not mean we can see the physical objects behind it; it means we can see through its appearance to its deepest nature. We see through the color and shape, as if its appearance suddenly becomes thinner, so thin it is transparent. We can look inside, so to speak, but then we simply see nothingness, an infinity of space. This shows that the normal opaqueness is due to cognitive filters, whose absence makes all objects transparent to their inner nature, their final constituency. We do not necessarily see the atoms and the elementary particles, for these are merely the smaller constituents of physical appearance, which also become transparent to reveal ultimate nature. 

The more important observation is that as the rock becomes transparent to its true nature our experience of it also changes in terms of substance. The rock not only looks transparent, it feels insubstantial. We lose our normal sense of it being a solid object, substantial and real. In other words, the sense of physical solidity, substantiality, and rock-like reality are also the result of cognitive filters. When we reify this particular form of appearance, separate it from the rest of manifestation, and think of it as an independently self-existing object, such cognitive conclusion imbues our perception of the rock with the feeling of substantial solidity. Without these cognitive positions, with total openness to the reality of the rock, our perception continues to be of the same rock, with the same shape and color, but we see it as transparent and we do not feel the customary feel or sense of solidity and substantiality. We perceive it to be of the nature of light, or of thought, light and insubstantial. 

From the perspective of the absolute, all manifest forms possess this insubstantiality and lightness, and all in the same degree. It is not as if rocks are insubstantial but more substantial than water. When it comes to the absolute perception they are all equal in their insubstantiality; this insubstantiality is simply our perception of their ontological ground, which is the same absolute everywhere. They are all totally insubstantial, for their ultimate status is nonbeing. More accurately, all forms are a coemergence of two things: appearance and nonbeing. Their appearance is their being, but their ground is nonbeing. Their appearance-presence is always accompanied with their nonbeing. They cannot be without nonbeing, for the nonbeing of the absolute is the ground of their being. Such understanding is totally paradoxical for our thematizing ordinary mind; but it is actually how things are, and how we will perceive them when we are free from all cognitive filters.