user12753: When reading the suttas, sometimes I come across to the expressions: 
"dimension of the infinitude of space",
"dimension of the infinitude of consciousness", 
"dimension of nothingness" and
"dimension of neither perception nor non-perception".
What exactly is the meaning of the expressions above? Why they are "formless"? 
When the Buddha describes Right Concentration, he mentions only the four "form" jhana, why he excluded the "formless" jhana as Right Concentration?

user13709: AN9.41 provides a wonderfully detailed experience of renunciation into and through these dimensions. 

Why don’t I, going totally beyond perceptions of form, with the ending of perceptions of impingement, not focusing on perceptions of diversity, aware that “space is infinite”, enter and remain in the dimension of infinite space?’

The sutta also deals with the doubts you've expressed and basically states that faith and a willingness to shift outlook and renounce is the key to understanding and experiencing each dimension. They're progressive.

I haven’t seen the drawbacks of forms, and so I haven’t cultivated that.

Which leads to the following encouragement: 

Suppose that, seeing the drawbacks of forms, I was to cultivate that. And suppose that, realizing the benefits of the dimension of infinite space, I was to develop that. It’s possible that my mind would be eager for the dimension of infinite space; it would be confident, settled, and decided about it. And I would see it as peaceful

Although we could discuss infinite space as the absence of forms, it wouldn't compare to actually experiencing that infinite space.
Note: this is inference, not experience. The earlier stuff has worked in this manner for me and has given me confidence to just keep going...

user16297: To understand the exact difference between the 4 rupa jhanas, and the arupa samadhi, the short formula for the 5th attainment, the base of infinite space, contains the details. The formula is too terse to understand on its own, so this article provides the glosses from other suttas that explain the detailed meaning of the formula. 
http://lucid24.org/sted/8aam/8samadhi/smd5/index.html
In short, rupa are the 4 elements and 31 body parts, and in the context of 4 jhanas, rupa and kaya are referring to the same physical body. In the arupa samadhis, attainemnts #5-9, the mind faculty is divorced from the 5 senses - you can't feel the breath,  you can't feel mosquito bites, you can't feel leg pain, you can't find your body spatially with kinasethetic sensation. 
As AN 5.28 jhana similes clearly describe explicitly, in 4 jhanas one does have kinaesthetic sensation of the anatomical body.

user-1: Going off sutta and abhidhamma;
Suppose a person would see a sight with the eye. If the person was to close the eye and recall in mind the forms that were seen, he could do that.
When he first saw with the eye, the 'eye' was implicated in contact with visible forms (shapes&colors).
When recalling the sight, the eye wasn't implicated, the contact was only at mind base and with ideation which was of shapes&colors as can be seen with the 'eye', resultant perception  is a different one from the ceased eye-consciousness but it was assosiated.
In arupa jhana the contact is also at the mind base and with ideation but the ideation has nothing to do with what is seen, heard, smelled, tasted or sensed with the body. 
It is said that at that time intellect is devorced from the five faculties (senses derived from the body).
In the first example the object of recollection was tied to what can be seen. In the case of arupajhana one won't perceive forms & colors anymore nor feel with the body or imagine or recall what has to do with the world of form in principle.
If we imagine what the perception of infinite space is like, we can only visualize it in terms of darkness or some other color/shape; we can visualize nothingness no more than we can paint a music piece but we can perceive it with intellect by the stilling/fading of the other elements, form element in particular, arupa jhana.
Fading of form is pretty much the fading of senses derived from the body and any ideation that may arise of and in regards to the bodily senses.
Ie one is percepient of only space in the 1st arupa jhana. 
Space unlike color&taste is of the mental sphere, is something we can't point to but we know it is there and can think about it, seeing it with intellect/discerning this space element when we think about what the senses present to make sense of what the senses present.
In this sense the space element can be seen with intellect, we know it plays part, comes into play, it is invisible but real. 
In terms of game engine development; it as if an element or class of elements no longer get rendered into being, so there is then only the rendering of the remaining "physics", no rendering of environment or world. Maybe this can be a helpful analogy but in the dhamma that which renders is also the rendered, the system being talked about is closed, autonimously directing and self sustaining one.
Each arupa jhana is conveived, felt & perceived differently.
As to Right Concentration.
The entering into & remaining in this or that jhana is also called "a pleasant abiding". 
And it's true that entering into & remaining in both rupa & arupajhana is called 'a pleasant abiding'; and only the entering into & remaining in rupa jhana is called Samma Samadhi (Right Concentration).
The Arupa Jhanas are probably not proclaimed to be a path constituent because they may be path for one person and not be the path for another.
In a sutta with Cunda(?) He askd whether those Arahants had magical powers or arupa jhanas and they being liberated by wisdom said no they didn't have the arupa jhanas, whereas other people do have these attainments not all arahts did; one can do without is the point.
Therefore it is probably not always true and is therefore not included in the universal expression of 8FNP. 
Afaik Abhidhamma delineates the path constituent of right concentration for arupa jhanas.

user2282: Since they're "formless", they can't really be "exactly" described right? :-) Anyway, Ven. Bodhi's "Noble Eightfold Path" gave some idea about what they are. Also, while the four jhanas make up the usual textual definition of right concentration, that doesn't mean SammaSamadhi only involves just those 4 exclusively.

"Beyond the four jhanas lie the four immaterial states, levels of absorption in which the mind transcends even the subtlest perception of visualized images still sometimes persisting in the jhanas. The immaterial states are attained, not by refining mental factors as are the jhanas, but by refining objects, by replacing a relatively gross object with a subtler one. The four attainments are named after their respective objects: the base of infinite space, the base of infinite consciousness, the base of nothingness, and the base of neither-perception-nor-non-perception.[65] These states represent levels of concentration so subtle and remote as to elude clear verbal explanation. The last of the four stands at the apex of mental concentration; it is the absolute, maximum degree of unification possible for consciousness. But even so, these absorptions reached by the path of serenity meditation, as exalted as they are, still lack the wisdom of insight, and so are not yet sufficient for gaining deliverance."


user43: Here is my understanding as of 2018.
When they say "form" (rupa) or "seed" (bija) in context of meditation, it's what we call an object of meditation these days. For example, your breath, an image of the Buddha, a particular repulsive image used as an antidote to lust - are all examples of meditation objects. An object of meditation is used as its focal point and directly correlates with the meditation's goal or objective.
Formless meditation, in contrast, is a type of meditation that involves no particular focal point, no object. As I understand, the formless jhanas refer to a step-by-step sequence of getting rid of any notion of object, however subtle. 
But before we can talk about formless meditation we need to talk about the ancient model describing the process of perception. In that model, the way we perceive things is by identifying a mark (aka sign) that serves as the main determining characteristic of an object, and by matching that mark against our memory of previous impressions, making an associative interpretation that what we're looking at (hearing, thinking about) can be described with such-and-such concept. This initial hypothesis is then confirmed by finding other secondary marks (signs) that the identified object must possess and confirming they lead to the same association. This process repeats in cycles until one of the associations expands into a related concept or a memory, which leads down some train of thoughts with its desires, fears, and other problematic mindstates.
Since thinking was understood to be the root of all evil, and yoga was defined as "citta vrtti nirodha" (stopping the ever unfolding associative cycle), getting rid of all objects was the chief method for stopping the thoughts. This was the state of the art before Buddha.
Now that we understand what we're dealing with, we can understand the sequence of formless jhanas. First, you visualize infinite empty space with no objects. This is a good approximation of objectlessness, but if you think about it, you still have an object on your mind - the image of empty space. In fact, this image of empty space consists of some kind of mental "mark" or "sign" that the meditator assumes to be a good associative hook (e.g. a tactile sensation of moving and encountering no contact, or a spatial image of endlessly expanding in all directions etc.) plus the concept "empty space" that we are interpreting that sign into. So, upon close examination this type of meditation is not very objectless as it still involves what's these days is called semiosis or the act of interpreting a sign into a meaning.
So as a next step, you meditate on the empty mind with no objects. It's a mind that is potentially capable of perception, it could potentially have an object but it does not. At first you successfully imagine such a mind and in contrast with meditation on empty space, this does seem to involve no sign and no act of interpretation. It seems like a truly objectless state. But then, as you keep meditating on it, you realize that in fact your meditation still does involve a subtle kind of "sign" that is interpreted into a concept! The idea that serves as a sign in this case is a notion of time passing with no objects appearing in/to the mind! So while this meditation is closer to objectlessness, it still has a kind of very subtle object - the notion of time passing. 
So you progress to meditation on Nothingness. You just sit there with no content whatsoever. Your mind is completely blank. There is no perception of space or time. It looks like, finally, you have succeeded. However, once you master that, you realize that this absence of content in fact disappears when you stop meditating, therefore your meditation still has a limit, still has a focal point. You still artificially restrict your attention to exclude whatever is going on, and that counts as form. It's a very-very subtle object, it's an object of no-object - but an object nevertheless. The thoughts are stopped while you're in meditation, but once you come out of this withdrawal, you're back to square one. So this state is non-sustainable.
So then, as the final step, you realize that complete withdrawal from all objects is not as effective as learning to stop the associative mechanism from cycling. So instead of trying to generate a state with no objects, you transcend that restriction and allow your attention to stay wide open to stimuli, without apprehending any single one of them. Things may happen as normal but you don't associate, don't conceptualize, don't get carried away by them. Your meditation is truly formless (objectless), because the mind is wide open without grasping at signs. Unfortunately, this state is still useless because you can't really function in it. Any human activity that requires association and interpretation is incompatible with this method of liberation.
This ends the progression and concludes the study of semiotic perception.
The reason Buddha de-emphasized this approach, which apparently was known before Buddha, is because it has no direct relevance in his own framework, that of the Four Noble Truths. In Buddha's system the principle problem of sentient existence is "wrongness" (dukkha) and the goal is "suchness". So in Buddha's sequence of jhanas, the progression is focused on working with sources of "wrongness" in one's mental continuum, his method is to abandon coarse and then progressively subtler sources of "wrongness" while generating coarse and then progressively subtler states of "suchness" (joy=>bliss=>peace=>etc).
The formless jhanas are a nice exercise in concentration and an easy example of progressively refined meditative sequence that many practitioners in Buddha's times must have been familiar with, but in and of themselves they do not lead to Liberation as Buddha defined it - permanent, unconditional cessation of dukkha.
This is why most traditional sources describe formless jhanas as optional. In the ancient metaphorical language, the subjective experience of meditator in a formless jhana is compared with that of a deity at a certain level of heavens, whose life has no suffering but is finite and inevitably ends with eventual return to Earth.
While Buddha's jhanas are a progressive unfolding of his Four Right Efforts:

"There is the case where a monk generates desire, endeavors, activates persistence, upholds & exerts his intent for:
  "[i] the sake of the non-arising [anuppādāya] of evil, unskillful qualities that have not yet arisen.
  "[ii] ... the sake of the abandonment [pahānāya] of evil, unskillful qualities that have arisen.
  "[iii] ... the sake of the arising [uppādāya] of skillful qualities that have not yet arisen.
  "[iv] ... the maintenance [ṭhitiyā], non-confusion, increase, plenitude, development, & culmination of skillful qualities that have arisen."  

And are a progressively closer approximation of the cessation of suffering declared in the Third Noble Truth.

Now this, bhikkhus, is the noble truth of the cessation of suffering: it is the remainderless fading away and cessation of that same craving, the giving up and relinquishing of it, freedom from it, non-reliance on it.

In Buddha's four jhanas (known by contrast with the others as the "rupa" or form-jhanas), you examine your mind, identify the immediate sources of dukkha (cravings, attachments, hangups, mental conflicts etc.), as well as the various factors hindering your progress (distractions, pessimism etc.) and let go of those, while at the same time finding ways to generate the positive qualities that help you keep going, such as Motivation, Energy, Attentiveness, etc. as well as the approximations of suchness such as Pride, Joy, and Peace.
The culmination of rupa jhanas is liberation in the suchness of spontaneous presence, which involves no feeling of "wrongness" whatsoever and is endlessly sustainable because it is not limited by any condition other than the absence of aversions and cravings for things to be otherwise.
So unlike arupa jhanas which solve the wrong problem in the wrong way, Buddha's jhanas succeed by focusing on the right issue (that of the "wrongness" or "rightness" of one's experience) and then progressively refining the practice until it culminates in a fully sustainable, truly unconditional liberation. 

12753: <p>When reading the suttas, sometimes I come across to the expressions: 
"dimension of the infinitude of space",
"dimension of the infinitude of consciousness", 
"dimension of nothingness" and
"dimension of neither perception nor non-perception".</p>

<p>What exactly is the meaning of the expressions above? Why they are "formless"? 
When the Buddha describes Right Concentration, he mentions only the four "form" jhana, why he excluded the "formless" jhana as Right Concentration?</p>
 13709: <p><a href="https://suttacentral.net/an9.41/en/sujato" rel="nofollow noreferrer">AN9.41</a> provides a wonderfully detailed experience of renunciation into and through these dimensions. </p>

<blockquote>
  <p>Why don’t I, going totally beyond perceptions of form, with the ending of perceptions of impingement, not focusing on perceptions of diversity, aware that “space is infinite”, enter and remain in the dimension of infinite space?’</p>
</blockquote>

<p>The sutta also deals with the doubts you've expressed and basically states that faith and a willingness to shift outlook and renounce is the key to understanding and experiencing each dimension. They're progressive.</p>

<blockquote>
  <p>I haven’t seen the drawbacks of forms, and so I haven’t cultivated that.</p>
</blockquote>

<p>Which leads to the following encouragement: </p>

<blockquote>
  <p>Suppose that, seeing the drawbacks of forms, I was to cultivate that. And suppose that, realizing the benefits of the dimension of infinite space, I was to develop that. It’s possible that my mind would be eager for the dimension of infinite space; it would be confident, settled, and decided about it. And I would see it as peaceful</p>
</blockquote>

<p>Although we could discuss infinite space as the absence of forms, it wouldn't compare to actually experiencing that infinite space.</p>

<p>Note: this is inference, not experience. The earlier stuff has worked in this manner for me and has given me confidence to just keep going...</p>
 16297: <p>To understand the exact difference between the 4 rupa jhanas, and the arupa samadhi, the short formula for the 5th attainment, the base of infinite space, contains the details. The formula is too terse to understand on its own, so this article provides the glosses from other suttas that explain the detailed meaning of the formula. 
<a href="http://lucid24.org/sted/8aam/8samadhi/smd5/index.html" rel="nofollow noreferrer">http://lucid24.org/sted/8aam/8samadhi/smd5/index.html</a></p>

<p>In short, rupa are the 4 elements and 31 body parts, and in the context of 4 jhanas, rupa and kaya are referring to the same physical body. In the arupa samadhis, attainemnts #5-9, the mind faculty is divorced from the 5 senses - you can't feel the breath,  you can't feel mosquito bites, you can't feel leg pain, you can't find your body spatially with kinasethetic sensation. </p>

<p>As AN 5.28 jhana similes clearly describe explicitly, in 4 jhanas one does have kinaesthetic sensation of the anatomical body.</p>
 -1: <p>Going off sutta and abhidhamma;</p>

<p>Suppose a person would see a sight with the eye. If the person was to close the eye and recall in mind the forms that were seen, he could do that.</p>

<p>When he first saw with the eye, the 'eye' was implicated in contact with visible forms (shapes&amp;colors).</p>

<p>When recalling the sight, the eye wasn't implicated, the contact was only at mind base and with ideation which was of shapes&amp;colors as can be seen with the 'eye', resultant perception  is a different one from the ceased eye-consciousness but it was assosiated.</p>

<p>In arupa jhana the contact is also at the mind base and with ideation but the ideation has nothing to do with what is seen, heard, smelled, tasted or sensed with the body. </p>

<p>It is said that at that time intellect is devorced from the five faculties (senses derived from the body).</p>

<p>In the first example the object of recollection was tied to what can be seen. In the case of arupajhana one won't perceive forms &amp; colors anymore nor feel with the body or imagine or recall what has to do with the world of form in principle.</p>

<p>If we imagine what the perception of infinite space is like, we can only visualize it in terms of darkness or some other color/shape; we can visualize nothingness no more than we can paint a music piece but we can perceive it with intellect by the stilling/fading of the other elements, form element in particular, arupa jhana.</p>

<p>Fading of form is pretty much the fading of senses derived from the body and any ideation that may arise of and in regards to the bodily senses.</p>

<p>Ie one is percepient of only space in the 1st arupa jhana. </p>

<p>Space unlike color&amp;taste is of the mental sphere, is something we can't point to but we know it is there and can think about it, seeing it with intellect/discerning this space element when we think about what the senses present to make sense of what the senses present.</p>

<p>In this sense the space element can be seen with intellect, we know it plays part, comes into play, it is invisible but real. </p>

<p>In terms of game engine development; it as if an element or class of elements no longer get rendered into being, so there is then only the rendering of the remaining "physics", no rendering of environment or world. Maybe this can be a helpful analogy but in the dhamma that which renders is also the rendered, the system being talked about is closed, autonimously directing and self sustaining one.</p>

<p>Each arupa jhana is conveived, felt &amp; perceived differently.</p>

<p><strong>As to Right Concentration.</strong></p>

<p>The entering into &amp; remaining in this or that jhana is also called "a pleasant abiding". </p>

<p>And it's true that entering into &amp; remaining in both rupa &amp; arupajhana is called 'a pleasant abiding'; and only the entering into &amp; remaining in rupa jhana is called Samma Samadhi (Right Concentration).</p>

<p>The Arupa Jhanas are probably not proclaimed to be a path constituent because they may be path for one person and not be the path for another.</p>

<p>In a sutta with Cunda(?) He askd whether those Arahants had magical powers or arupa jhanas and they being liberated by wisdom said no they didn't have the arupa jhanas, whereas other people do have these attainments not all arahts did; one can do without is the point.</p>

<p>Therefore it is probably not always true and is therefore not included in the universal expression of 8FNP. </p>

<p>Afaik Abhidhamma delineates the path constituent of right concentration for arupa jhanas.</p>
 2282: <p>Since they're "formless", they can't really be "exactly" described right? :-) Anyway, Ven. Bodhi's "<a href="https://www.accesstoinsight.org/lib/authors/bodhi/waytoend.html" rel="nofollow noreferrer">Noble Eightfold Path</a>" gave some idea about what they are. Also, while the four jhanas make up the usual textual definition of right concentration, that doesn't mean SammaSamadhi only involves just those 4 exclusively.</p>

<blockquote>
  <p>"Beyond the four jhanas lie the four immaterial states, levels of absorption in which the mind transcends even the subtlest perception of visualized images still sometimes persisting in the jhanas. The immaterial states are attained, not by refining mental factors as are the jhanas, but by refining objects, by replacing a relatively gross object with a subtler one. The four attainments are named after their respective objects: the base of infinite space, the base of infinite consciousness, the base of nothingness, and the base of neither-perception-nor-non-perception.[65] These states represent levels of concentration so subtle and remote as to elude clear verbal explanation. The last of the four stands at the apex of mental concentration; it is the absolute, maximum degree of unification possible for consciousness. But even so, these absorptions reached by the path of serenity meditation, as exalted as they are, still lack the wisdom of insight, and so are not yet sufficient for gaining deliverance."</p>
</blockquote>
 43: <p>Here is my understanding as of 2018.</p>

<p>When they say "form" (rupa) or "seed" (bija) in context of meditation, it's what we call <em>an object</em> of meditation these days. For example, your breath, an image of the Buddha, a particular repulsive image used as an antidote to lust - are all examples of meditation objects. An object of meditation is used as its focal point and directly correlates with the meditation's goal or objective.</p>

<p>Formless meditation, in contrast, is a type of meditation that involves no particular focal point, no object. As I understand, the formless jhanas refer to a step-by-step sequence of getting rid of any notion of object, however subtle. </p>

<p>But before we can talk about formless meditation we need to talk about the ancient model describing the process of perception. In that model, the way we perceive things is by identifying a mark (aka sign) that serves as the main determining characteristic of an object, and by matching that mark against our memory of previous impressions, making an associative interpretation that what we're looking at (hearing, thinking about) can be described with such-and-such concept. This initial hypothesis is then confirmed by finding other secondary marks (signs) that the identified object must possess and confirming they lead to the same association. This process repeats in cycles until one of the associations expands into a related concept or a memory, which leads down some train of thoughts with its desires, fears, and other problematic mindstates.</p>

<p>Since thinking was understood to be the root of all evil, and yoga was defined as "citta vrtti nirodha" (stopping the ever unfolding associative cycle), getting rid of all objects was the chief method for stopping the thoughts. This was the state of the art before Buddha.</p>

<p>Now that we understand what we're dealing with, we can understand the sequence of formless jhanas. First, you visualize infinite empty space with no objects. This is a good approximation of objectlessness, but if you think about it, you still have an object on your mind - the image of empty space. In fact, this image of empty space consists of some kind of mental "mark" or "sign" that the meditator assumes to be a good associative hook (e.g. a tactile sensation of moving and encountering no contact, or a spatial image of endlessly expanding in all directions etc.) plus the concept "empty space" that we are interpreting that sign into. So, upon close examination this type of meditation is not very objectless as it still involves what's these days is called <em>semiosis</em> or the act of interpreting a sign into a meaning.</p>

<p>So as a next step, you meditate on the empty mind with no objects. It's a mind that is potentially capable of perception, it could potentially have an object but it does not. At first you successfully imagine such a mind and in contrast with meditation on empty space, this does seem to involve no sign and no act of interpretation. It seems like a truly objectless state. But then, as you keep meditating on it, you realize that in fact your meditation still <em>does</em> involve a subtle kind of "sign" that is interpreted into a concept! The idea that serves as a sign in this case is a notion of time passing with no objects appearing in/to the mind! So while this meditation is closer to objectlessness, it still has a kind of very subtle object - the notion of time passing. </p>

<p>So you progress to meditation on Nothingness. You just sit there with no content whatsoever. Your mind is completely blank. There is no perception of space or time. It looks like, finally, you have succeeded. However, once you master that, you realize that this absence of content in fact disappears when you stop meditating, therefore your meditation still has a limit, still has a focal point. You still artificially restrict your attention to exclude whatever is going on, and that counts as form. It's a very-very subtle object, it's an object of no-object - but an object nevertheless. The thoughts are stopped while you're in meditation, but once you come out of this withdrawal, you're back to square one. So this state is non-sustainable.</p>

<p>So then, as the final step, you realize that complete withdrawal from all objects is not as effective as learning to stop the associative mechanism from cycling. So instead of trying to generate a state with no objects, you transcend that restriction and allow your attention to stay wide open to stimuli, without apprehending any single one of them. Things may happen as normal but you don't associate, don't conceptualize, don't get carried away by them. Your meditation is truly formless (objectless), because the mind is wide open without grasping at signs. Unfortunately, this state is still useless because you can't really function in it. Any human activity that requires association and interpretation is incompatible with this method of liberation.</p>

<p>This ends the progression and concludes the study of semiotic perception.</p>

<p>The reason Buddha de-emphasized this approach, which apparently was known before Buddha, is because it has no direct relevance in his own framework, that of the Four Noble Truths. In Buddha's system the principle problem of sentient existence is "wrongness" (dukkha) and the goal is "suchness". So in Buddha's sequence of jhanas, the progression is focused on working with sources of "wrongness" in one's mental continuum, his method is to abandon coarse and then progressively subtler sources of "wrongness" while generating coarse and then progressively subtler states of "suchness" (joy=>bliss=>peace=>etc).</p>

<p>The formless jhanas are a nice exercise in concentration and an easy example of progressively refined meditative sequence that many practitioners in Buddha's times must have been familiar with, but in and of themselves they do not lead to Liberation as Buddha defined it - permanent, unconditional cessation of dukkha.</p>

<p>This is why most traditional sources describe formless jhanas as optional. In the ancient metaphorical language, the subjective experience of meditator in a formless jhana is compared with that of a deity at a certain level of heavens, whose life has no suffering but is finite and inevitably ends with eventual return to Earth.</p>

<p>While Buddha's jhanas are a progressive unfolding of his Four Right Efforts:</p>

<blockquote>
  <p>"There is the case where a monk generates desire, endeavors, activates persistence, upholds &amp; exerts his intent for:<br>
  "[i] the sake of the non-arising [anuppādāya] of evil, unskillful qualities that have not yet arisen.<br>
  "[ii] ... the sake of the abandonment [pahānāya] of evil, unskillful qualities that have arisen.<br>
  "[iii] ... the sake of the arising [uppādāya] of skillful qualities that have not yet arisen.<br>
  "[iv] ... the maintenance [ṭhitiyā], non-confusion, increase, plenitude, development, &amp; culmination of skillful qualities that have arisen."  </p>
</blockquote>

<p>And are a progressively closer approximation of the cessation of suffering declared in the Third Noble Truth.</p>

<blockquote>
  <p>Now this, bhikkhus, is the noble truth of the cessation of suffering: it is the remainderless fading away and cessation of that same craving, the giving up and relinquishing of it, freedom from it, non-reliance on it.</p>
</blockquote>

<p>In Buddha's four jhanas (known by contrast with the others as the "rupa" or form-jhanas), you examine your mind, identify the immediate sources of dukkha (cravings, attachments, hangups, mental conflicts etc.), as well as the various factors hindering your progress (distractions, pessimism etc.) and let go of those, while at the same time finding ways to generate the positive qualities that help you keep going, such as Motivation, Energy, Attentiveness, etc. as well as the approximations of suchness such as Pride, Joy, and Peace.</p>

<p>The culmination of rupa jhanas is liberation in the suchness of spontaneous presence, which involves no feeling of "wrongness" whatsoever and is endlessly sustainable because it is not limited by any condition other than the absence of aversions and cravings for things to be otherwise.</p>

<p>So unlike arupa jhanas which solve the wrong problem in the wrong way, Buddha's jhanas succeed by focusing on the right issue (that of the "wrongness" or "rightness" of one's experience) and then progressively refining the practice until it culminates in a fully sustainable, truly unconditional liberation. </p>
