I find this wonderful from a section of a 1982 paper by Frederick J. Streng titled "Three approaches to authentic existence: Christian, Confucian, and Buddhist." It tries to point a finger toward how things are "inside" Nishitani's "field or emptiness":
... the "field of emptiness" is not a substantive reality, but much more a state of consciousness which gives a certain quality or character to the arising and dissipation of existence. The emptiness which Nishitani talks about is not a nihilum as in the notion of nihilism. Rather it is a continual emptying of the self-centered grasp of personality and attachments to things. The interplay between the affirmative and negative aspects in emptiness, however, is perceived only when one realizes that it requires a complete negation of any abstraction of emptiness or being-in-itself. Thus, this is a radical kind of negativity which seeks to plumb the very depths of a notion of emptiness by negating even "emptiness" as a notion. Only by negating the particular forms of one's experience can one get beyond the negation itself to a sense that there is an intrinsic relatedness between all things. One must pass through the nihilism of nihilistic existentialism, which, in simply negating essences, judges life to be absurd. Nishitani claims that once a person passes through the claim of absolute negativity as the opposite to a universal essence (that is, "being-itself"), then one does not perceive life as absurd when confronted with nonbeing; nor need a person develop his or her ego strength as a superman or wonder woman. Rather, a new "mode of being" (nonattaching to being-itself) takes form as one moves through the depth of nihilism.
The deep realization of the emptiness of everything makes it possible to penetrate the ontological reality of all particular things while at the same time affirming the relative reality of particular things in existence. Emptiness, as understood here, is not a reality as being-itself, nor as a part of the intrinsic rhythm of all change; there is no reality outside the language system that correlates with the notion of emptiness. This is affirmed not because there is nothing whatsoever outside the language system, but because words are seen to be powerful, but inaccurate, constructors of experienced reality. Ontological terms should not be seen primarily as indicators of some thing outside of the language system in a one-to-one correlation with any concept. Thus, to perceive the nature of emptiness--in distinction to the notion of "emptinees"--is to avoid identifying this term with some presumed substance or principle. As soon as emptiness is taken as a reality either in the subject or as a reality outside of the self, it is no longer the root source for both the subjective and objective experience.
The effort to avoid both an absolute nihilism and a simply negative pole of an essentialism is matched only by the intensity with which Nishitani affirms that one must perceive the relationships between particular things while at the same time maintaining their particularity. He says that from the standpoint of emptiness, each thing is itself while not being itself, is not itself while being itself; its 'being' is unreal in its truth and true in its unreality. This may sound queer at first but, in fact, through such a view, we are enabled for the first time to conceive a 'force' by virtue of which all things are gathered and brought into relationship to one another--a 'force' which, since ancient times, has been called nature (physis, natura).
If one were not to assume this intrinsic relatedness through the "ground of emptiness," Nishitani is ready to admit, something would exist "in-itself," namely, when it is separate from everything outside of itself. In the everyday conventional subject-object awareness, the identification of something-in-itself is significant because it excludes what is not-itself. This results in a total lack of being able to perceive the nature of anything outside of oneself, and finally ends up in a chaotic awareness. "Only on the field of emptiness," Nishitani continues, "where being is being-nothingness as well as nothingness-being, is it possible that each being is itself in the face of all the others, and thus, at the same time, is not itself to all the others."
The result of perceiving the world from this standpoint is that the uniqueness of a thing requires that it is situated as the root center of all other things. The relationship that particular unique things have with each other while being essentially interrelated is called "circuminsessional'' by Nishitani. When a particular thing recognizes its basic character as "no-self nature" it recognizes that its being is one with emptiness; by letting go of its own "self" it becomes a participant in the center of all other unique particulars. From the standpoint of emptiness, then, a thing "is" in terms of its own "selfhood" when it both is subordinate to all other things and at the same time becomes the center for all other things.
Since the field of emptiness is also identified as the field of the "circuminsessional relationship," all things manifest their own reality when they have let go of grasping after some unique essence of themselves and found their own absolute selfhood in complete interrelatedness. The mode of being which is the genuine "suchness" of a thing is that it is inaccessible to identifying it simply with either the subject or the object; rather something really "is" when it is identical with itself and at the same time with other things. All things in the world, then, are seen to be interrelated. To be interrelated means being both the center and the supportive aspect of, or subordinate to, another thing at the same time. The absolute interdependency that one thing has with another for its own unique selfhood is expressed by the term "circuminsessional," in which "all things in their 'being' thus enter into another home-ground, are not themselves and, nevertheless precisely as such (i.e., on the field of emptiness) are themselves to the very end." This web of circuminsessional interpenetration is called by Nishitani a "mode of being"; it is "the thing's in-itself mode of being, its nonobjective mode of being as 'middle,' its selfness."