The explanation of the eight meditative states (form realm meditation and formless realm meditation) based on Theravada Buddhism is based on the Suttanipata scripture. However, the same scripture is explained by Honzan Hiroshi, and I find his explanation more understandable.

First, Honzan Hiroshi points out that Buddhism distinguishes between the "desire realm," and he argues that the desire realm should be included in the form realm. The form realm corresponds to "matter," and is equivalent to the astral realm and the causal realm (according to Honzan Hiroshi's definition). "Color" refers to matter. The astral realm is mainly the world of emotions, while "karana" is a Sanskrit word meaning "cause," which corresponds to the "causal realm" in Theosophy. According to him, the causal realm is considered "matter."

■ Buddhism
Desire Realm
Form Realm
Formless Realm

■ Honzan Hiroshi
Form Realm (including the Desire Realm)
Formless Realm

Based on this, he explains the four form realm meditations as follows:

First Meditation: A state where you experience a state of not thinking for even a few seconds.
Second Meditation: A state where you momentarily stop distracting thoughts and feel pleasant. This is an emotion, so it seems to correspond to the astral dimension.
Third Meditation: A stage where you go beyond the pleasantness of the second meditation and a direct perception of things emerges.
Fourth Meditation: A state where you can distinguish between what is truly right and wrong, and what is universal and impermanent to some extent. This corresponds to the beginning of the astral upper realm or the causal dimension.
(Based on the interpretation of "Honzan Hiroshi's Collected Works 7")

In my own words, these correspond to the following:

First Meditation: Temporary peace through concentration.
Second Meditation: Bliss through being in the zone.
Third Meditation: The emotional bliss of being in the zone subsides, and wisdom deepens.
Fourth Meditation: A state of tranquility (direct perception also increases).

■ The Four Formless Meditations

Next, the overview of the four formless meditations in the same book is as follows:

First, the four formless meditations correspond to something beyond the causal realm, and more specifically, to the purusha in yoga.

In Buddhism, the formless meditations are described as "beyond matter." However, in Honzan Hiroshi's classification, the causal realm is still considered matter, and it has a physical body. However, there is a difference in that the astral realm, which corresponds to the form realm, has a strong influence of matter, while in the causal realm, even though it is matter, the influence of matter is much weaker, and the power of the spirit is stronger.

The formless realm corresponds to a state where, although it still has a physical body in the causal world, the power of the spirit is stronger. The four formless meditations are based on this formless realm. This is Honzan Hiroshi's interpretation, which is different from the Buddhist interpretation, but I find his explanation more understandable.

■Emptiness Beyond Measure (Kūmuhenjyo)
The world becomes empty through the thought that the mind is the emptiness of the world, but the mind that thinks the world is empty does not disappear. (Excerpt from the same book)

It is said that this explanation is deeply reflected in the Buddhist worldview that "matter is created by thought."
Originally, matter exists independently as matter, but based on a purely mental perspective, the existence of matter is attributed to the mind, which leads to this kind of stage.

When reading the explanation, it seems more straightforward to interpret it as "entering a world without things, that is, the mind has reached beyond the power of things, a kind of Purusha state" (excerpt from the same book).
Even if it is temporary, this stage is equivalent to that.
In other words, it can be said to be "a stage where emptiness is directly perceived temporarily."

■Emptiness Beyond Perception (Shikimuhonjyo)
A state where all thoughts and perceptions, such as consciousness and thought, have completely ceased. (Excerpt from the same book)

In the previous stage, the movement of "the thinking mind" itself has stopped.

■Emptiness of Possession (Mujōjyo)
A state where the mind's activity continues for several minutes to several hours. (Excerpt from the same book)

■Emptiness Beyond Thought and Non-Thought (Hishōhishōjyo)
Discernment is made in the dimension of Purusha. (Excerpt from the same book)

■Emptiness Beyond Perception is the beginning of the realm of God.

When I look at these stages again, I used to interpret them in a Theravada Buddhist style, and I sometimes felt that I was somewhat achieving the stage of Emptiness Beyond Thought and Non-Thought.
However, based on the company's teachings of Honzan Haku Sensei, I feel that I have only reached the stage of Emptiness Beyond Perception, and that Emptiness of Possession is something I will achieve from now on.
However, when I read the explanation, it says that the mind stops...
Since I often meditate and time passes quickly, such as 1 hour or 2 hours, I may be gradually achieving Emptiness of Possession.

Also, Emptiness Beyond Perception seems to be a state that is easily achieved when the aura gathers around the Sahasrara chakra.
If that is the case, it seems that Emptiness of Possession is not achieved to that extent.

The following points should be noted regarding this:

Even if one has become free from thoughts and perceptions, as long as desires and attachments remain in the physical dimension, the astral dimension, and even the Karana dimension, one will never reach the state that is being described here, nor can one become one with God. (Excerpt from the same book)

At this stage, the union with God is not a special experience that can be seen or heard, and it is different from the experience of the four dhyanas in the realm of form. Also, in the realm of form, one has a body and therefore needs to go outside, but in the state of being one with the Purusha, oneself and the outside become one.

The state of Samadhi of the realm of consciousness and the state of Samadhi of non-attachment are the beginning of union with God, and the state of Samadhi of neither perception nor non-perception may be considered a sufficiently high state. However, according to Professor Honzan Hakuda, the state of Samadhi of neither perception nor non-perception is a stage just before enlightenment, and it has an important meaning in terms of personal union with the Purusha.

Furthermore, based on the Buddhist interpretation of idealism, it does not recognize the viewpoint that matter exists independently of the mind, and it states that "the three realms are manifestations of the mind." Therefore, it cannot become a science or a global religion, and it is necessary to overcome its limitations.

The state of Samadhi of neither perception nor non-perception is a state just before enlightenment, and it should be considered to have important meaning. Although different schools may assign ranks and positions, it should be a truly important stage for those who are seeking enlightenment, rather than a sophistry.

When I look at the interpretations of Professor Honsan Hiroshi in this way, it seems that for many people, the "non-thought, non-non-thought" state is about the limit, and that is quite sufficient. That is already a very high level of attainment, and if one can go beyond that, that's just a bonus.