user13375: This question is closely related to this question and this question and this question.
There is a Sutta in the Pali Canon that seems to explicitly reject that any of the aggregates is real or substantially existent, but instead likening them to a lump of foam, a water bubble, a mirage, a plantain trunk, or an illusion:

“Form is like a lump of foam, Feeling like a water bubble; Perception
  is like a mirage, Volitions like a plantain trunk, And consciousness
  like an illusion, So explained the Kinsman of the Sun.
“However one may ponder it And carefully investigate it, It appears
  but hollow and void When one views it carefully.
“With reference to this body The One of Broad Wisdom has taught That
  with the abandoning of three things One sees this form discarded.
“When vitality, heat, and consciousness Depart from this physical
  body, Then it lies there cast away: Food for others, without volition.
“Such is this continuum, This illusion, beguiler of fools. It is
  taught to be a murderer; Here no substance can be found.
“A bhikkhu with energy aroused Should look upon the aggregates thus,
  Whether by day or at night, Comprehending, ever mindful.
“He should discard all the fetters And make a refuge for himself; Let
  him fare as with head ablaze, Yearning for the imperishable state.”

Depending upon the answers to the previous questions I'd be very interested in how Theravada interprets this Sutta. Generally, I'm confused how Theravada interprets these Suttas into a coherent and non-contradictory whole:

SN 22.85 seems to say that regarding a Realized One as real or genuine is incorrect.
Itivuttaka 44 seems to say that (as per Ruben2020's answer here) the body is real and genuine.
SN 22.95 seems to reject that and say the body is to be considered like foam as "void, hollow, insubstantial."

Finally, Mahayana monastics train believing that the substantial difference between Theravada views of anatta and Mahayana views of shunyata is that Theravada regards the aggregates and all external phenomena as real and possessing intrinsic nature or essence.
How do Theravada proponents reconcile all of this?

user254: I see this sutta not as an objective or ontological statement (e.g. form is "real" or "unreal", "true" or untrue) but rather as subjective and prescriptive -- e.g. I see it as saying that "form, and feelings etc., are fragile and unreliable -- so don't crave them, don't attach to them, and don't depend on them."
I guess the interesting or most relevant bit (for the purpose of this question) is found here:

for no substance is found here.
sāro ettha na vijjati.

And see here for a definition of sāra.
I (personally) don't interpret this word as meaning "substance", in what I imagine is a philosophical sense (e.g. ontology) -- instead I interpret it as kind of subjective or pragmatic, e.g. as meaning "the bit that's useful to us, the part that proves to be reliable or everlasting, the valuable/worthwhile bit".
Part of the "true Scotsman" argument wanders into defining what a Scotsman "is", what it even means to "be" a Scotsman -- what's the "essential characteristic" (or "sign") of a Scotsman -- and who knows what a "real", "genuine", or "true" Scotsman is?
Conversely I think that according to Theravada the "characteristic" of everything is simple -- i.e. it's:

Impermanent
Not self (not "me" and not "mine")
Dukkha

Discussing whether the arrow is "real" (and what it's made of) is a bit of a distraction -- this commentary claims that Gautama Buddha's views were "anti-metaphysical".

Cula-Malunkyovada Sutta (MN 63)
And why are they undeclared by me? Because they are not connected with the goal, are not fundamental to the holy life. They do not lead to disenchantment, dispassion, cessation, calming, direct knowledge, self-awakening, Unbinding. That's why they are undeclared by me.
"And what is declared by me? 'This is stress,' is declared by me. 'This is the origination of stress,' is declared by me. 'This is the cessation of stress,' is declared by me. 'This is the path of practice leading to the cessation of stress,' is declared by me. And why are they declared by me? Because they are connected with the goal, are fundamental to the holy life. They lead to disenchantment, dispassion, cessation, calming, direct knowledge, self-awakening, Unbinding. That's why they are declared by me.
"So, Malunkyaputta, remember what is undeclared by me as undeclared, and what is declared by me as declared."

I'm not saying that your question is useless or unanswerable -- this one is not one of the canonical 14 unanswered questions -- just that it seems metaphysical to me, and asking questions that aren't answered n the text.
I guess if you analyse everything using a Mahayana-orthodox "analytic knife" then it will end up looking like a primitive/incomplete simulacrum of Mahayana doctrine -- but I think that the "posits" you're making maybe aren't present in the text -- furthermore the Simsapa Sutta (Handful of Leaves) is meant to assure us that what is in the text is sufficient (or "self-sufficient" if you will).

user-1: You wanted me to answer this one as well.
[Note: I didn't read all the suttas you've linked to, nor did I read all comments already posted.]

“Form is like a lump of foam, Feeling like a water bubble; Perception is like a mirage, Volitions like a plantain trunk, And consciousness like an illusion, So explained the Kinsman of the Sun.

Are the 5 aggregates substantial or not?
Imho, it's important to know from what point of view someone looks at things. Is it from the normal, everyday-of-life or intellectual, scholar point of view or the experiential point of view. That makes a huge difference.
From an experiential point of view things have only a momentary existence. They arise, leave an impression and cease again. They come and go.
Is there a body? No, experientially speaking there is, so now and then, a feeling of pressure, cold or warm, soft or hard in different locations (wind, fire, earth). At the moment of contact we can know those sensations. At the moment of contact there is something there. And then it's gone. Outside the knowing and the sense impression that can be known, there is nothing.
Are those sense impressions real? Well, yes. For that short moment there was contact, there was something to be known, and that something had an effect.
Are they substantial? No.
Same goes for all other aggregates.
I'm sure that from an intellectual point of view much more could be said. But, as you know, I'm not a scholar. So, it's not my place to get into that.

user471: Piya Tan in his commentary on the lump of foam sutta, quoted Bhikkhu Bodhi's commentary below:

This sutta is one of the most radical discourses on the empty nature
  of conditioned phenomena; its imagery (especially the similes of the
  mirage and the magical illusion) has been taken up by later Buddhist
  thinkers, most persistently by the Madhyamikas. Some of the images are
  found  elsewhere in the Pali Canon, eg at Dh 46, 170. In the context
  of early Buddhist thought, these similes have to be handled with care.
  They are not intended to suggest an illusionist view of the world but
  to show that our conceptions of the world, and of our own existence,
  are largely distorted by the processes of cognition. Just as the
  mirage and magical illusion are based on real existents — the sand of
  the desert, the magician’s appurtenances — so these false conceptions
  arise from a base that objectively exists, namely, the five
  aggregates; but when seen through a mind subject to conceptual
  distortion, the aggregates appear in a way that deviates from their
  actual nature. Instead of being seen as transient and selfless, they
  appear as substantial and as a self. (Bodhi S:B 1085 n188)

I think the above commentary discusses the Theravada view accurately. The sutta does not talk of an illusionist view of the world. It does not imply that the five aggregates are not real. It simply points towards the five aggregates as being transient and without a self.
Also, please see the Suñña Sutta, which explains this more literally, as the five aggregates being empty of a self.

13375: <p>This question is closely related to <a href="https://buddhism.stackexchange.com/questions/28699/does-any-real-existent-or-genuine-person-end-with-parinibbana">this question</a> and <a href="https://buddhism.stackexchange.com/questions/28708/does-theravada-posit-the-selflessness-of-phenomena">this question</a> and <a href="https://buddhism.stackexchange.com/questions/28707/difference-between-theravadas-self-and-mahayanas-intrinsic-essence">this question.</a></p>

<p>There is a <a href="https://suttacentral.net/sn22.95/en/bodhi" rel="nofollow noreferrer">Sutta in the Pali Canon</a> that seems to explicitly reject that any of the aggregates is real or substantially existent, but instead likening them to a lump of foam, a water bubble, a mirage, a plantain trunk, or an illusion:</p>

<blockquote>
  <p>“Form is like a lump of foam, Feeling like a water bubble; Perception
  is like a mirage, Volitions like a plantain trunk, And consciousness
  like an illusion, So explained the Kinsman of the Sun.</p>
  
  <p>“However one may ponder it And carefully investigate it, It appears
  but hollow and void When one views it carefully.</p>
  
  <p>“With reference to this body The One of Broad Wisdom has taught That
  with the abandoning of three things One sees this form discarded.</p>
  
  <p>“When vitality, heat, and consciousness Depart from this physical
  body, Then it lies there cast away: Food for others, without volition.</p>
  
  <p>“Such is this continuum, This illusion, beguiler of fools. It is
  taught to be a murderer; Here no substance can be found.</p>
  
  <p>“A bhikkhu with energy aroused Should look upon the aggregates thus,
  Whether by day or at night, Comprehending, ever mindful.</p>
  
  <p>“He should discard all the fetters And make a refuge for himself; Let
  him fare as with head ablaze, Yearning for the imperishable state.”</p>
</blockquote>

<p>Depending upon the answers to the previous questions I'd be very interested in how Theravada interprets this Sutta. Generally, I'm confused how Theravada interprets these Suttas into a coherent and non-contradictory whole:</p>

<ul>
<li>SN 22.85 seems to say that regarding a Realized One as real or genuine is incorrect.</li>
<li>Itivuttaka 44 seems to say that (as per Ruben2020's <a href="https://buddhism.stackexchange.com/a/28701/13375">answer here</a>) the body is real and genuine.</li>
<li>SN 22.95 seems to reject that and say the body is to be considered like foam as "void, hollow, insubstantial."</li>
</ul>

<p>Finally, Mahayana monastics train believing that the substantial difference between Theravada views of anatta and Mahayana views of shunyata is that Theravada regards the aggregates and all external phenomena as real and possessing intrinsic nature or essence.</p>

<p>How do Theravada proponents reconcile all of this?</p>
 254: <p>I see this sutta not as an objective or ontological statement (e.g. form is &quot;real&quot; or &quot;unreal&quot;, &quot;true&quot; or untrue) but rather as subjective and prescriptive -- e.g. I see it as saying that &quot;form, and feelings etc., are fragile and unreliable -- so don't crave them, don't attach to them, and don't depend on them.&quot;</p>
<p>I guess the interesting or most relevant bit (for the purpose of this question) is found here:</p>
<blockquote>
<p>for no substance is found here.<br />
<em>sāro ettha na vijjati</em>.</p>
</blockquote>
<p>And <a href="https://suttacentral.net/define/s%C4%81ra" rel="nofollow noreferrer">see here</a> for a definition of <em>sāra</em>.</p>
<p>I (personally) don't interpret this word as meaning &quot;substance&quot;, in what I imagine is a philosophical sense (e.g. <a href="https://en.wikipedia.org/wiki/Ontology" rel="nofollow noreferrer">ontology</a>) -- instead I interpret it as kind of subjective or pragmatic, e.g. as meaning &quot;the bit that's useful to us, the part that proves to be reliable or everlasting, the valuable/worthwhile bit&quot;.</p>
<p>Part of the &quot;true Scotsman&quot; argument wanders into defining what a Scotsman &quot;is&quot;, what it even means to &quot;be&quot; a Scotsman -- what's the &quot;essential characteristic&quot; (or &quot;sign&quot;) of a Scotsman -- and who knows what a &quot;real&quot;, &quot;genuine&quot;, or &quot;true&quot; Scotsman is?</p>
<p>Conversely I think that according to Theravada the &quot;characteristic&quot; of everything is simple -- i.e. it's:</p>
<ul>
<li>Impermanent</li>
<li>Not self (not &quot;me&quot; and not &quot;mine&quot;)</li>
<li>Dukkha</li>
</ul>
<p>Discussing whether the arrow is &quot;real&quot; (and what it's made of) is a bit of a distraction -- <a href="https://en.wikipedia.org/wiki/Ontology" rel="nofollow noreferrer">this commentary</a> claims that Gautama Buddha's views were &quot;anti-metaphysical&quot;.</p>
<blockquote>
<p><a href="https://www.accesstoinsight.org/tipitaka/mn/mn.063.than.html" rel="nofollow noreferrer">Cula-Malunkyovada Sutta (MN 63)</a></p>
<p>And why are they undeclared by me? Because they are not connected with the goal, are not fundamental to the holy life. They do not lead to disenchantment, dispassion, cessation, calming, direct knowledge, self-awakening, Unbinding. That's why they are undeclared by me.</p>
<p>&quot;And what is declared by me? 'This is stress,' is declared by me. 'This is the origination of stress,' is declared by me. 'This is the cessation of stress,' is declared by me. 'This is the path of practice leading to the cessation of stress,' is declared by me. And why are they declared by me? Because they are connected with the goal, are fundamental to the holy life. They lead to disenchantment, dispassion, cessation, calming, direct knowledge, self-awakening, Unbinding. That's why they are declared by me.</p>
<p>&quot;So, Malunkyaputta, remember what is undeclared by me as undeclared, and what is declared by me as declared.&quot;</p>
</blockquote>
<p>I'm not saying that your question is useless or unanswerable -- this one is not one of the canonical 14 unanswered questions -- just that it seems metaphysical to me, and asking questions that aren't answered n the text.</p>
<p>I guess if you analyse everything using a Mahayana-orthodox &quot;analytic knife&quot; then it will end up looking like a primitive/incomplete simulacrum of Mahayana doctrine -- but I think that the &quot;posits&quot; you're making maybe aren't present in the text -- furthermore the Simsapa Sutta (Handful of Leaves) is meant to assure us that what <em>is</em> in the text is sufficient (or &quot;self-sufficient&quot; if you will).</p>
 -1: <p>You wanted me to answer this one as well.
[Note: I didn't read all the suttas you've linked to, nor did I read all comments already posted.]</p>

<blockquote>
  <p>“Form is like a lump of foam, Feeling like a water bubble; Perception is like a mirage, Volitions like a plantain trunk, And consciousness like an illusion, So explained the Kinsman of the Sun.</p>
</blockquote>

<p>Are the 5 aggregates substantial or not?
Imho, it's important to know from what point of view someone looks at things. Is it from the normal, everyday-of-life or intellectual, scholar point of view or the experiential point of view. That makes a huge difference.
From an experiential point of view things have only a momentary existence. They arise, leave an impression and cease again. They come and go.</p>

<p>Is there a body? No, experientially speaking there is, so now and then, a feeling of pressure, cold or warm, soft or hard in different locations (wind, fire, earth). At the moment of contact we can know those sensations. At the moment of contact there is something there. And then it's gone. Outside the knowing and the sense impression that can be known, there is nothing.</p>

<p>Are those sense impressions real? Well, yes. For that short moment there was contact, there was something to be known, and that something had an effect.
Are they substantial? No.</p>

<p>Same goes for all other aggregates.</p>

<p>I'm sure that from an intellectual point of view much more could be said. But, as you know, I'm not a scholar. So, it's not my place to get into that.</p>
 471: <p>Piya Tan in <a href="http://www.themindingcentre.org/dharmafarer/wp-content/uploads/2009/12/17.12-Phenapinda-S-s22.95-piya.pdf" rel="nofollow noreferrer">his commentary on the lump of foam sutta</a>, quoted Bhikkhu Bodhi's commentary below:</p>

<blockquote>
  <p>This sutta is one of the most radical discourses on the empty nature
  of conditioned phenomena; its imagery (especially the similes of the
  mirage and the magical illusion) has been taken up by later Buddhist
  thinkers, most persistently by the Madhyamikas. Some of the images are
  found  elsewhere in the Pali Canon, eg at Dh 46, 170. In the context
  of early Buddhist thought, these similes have to be handled with care.
  <strong>They are not intended to suggest an illusionist view of the world</strong> but
  to show that our conceptions of the world, and of our own existence,
  are largely distorted by the processes of cognition. Just as the
  mirage and magical illusion are based on real existents — the sand of
  the desert, the magician’s appurtenances — <strong>so these false conceptions
  arise from a base that objectively exists</strong>, namely, the five
  aggregates; but when seen through a mind subject to conceptual
  distortion, the aggregates appear in a way that deviates from their
  actual nature. <strong>Instead of being seen as transient and selfless, they
  appear as substantial and as a self.</strong> (Bodhi S:B 1085 n188)</p>
</blockquote>

<p>I think the above commentary discusses the Theravada view accurately. The sutta does not talk of an illusionist view of the world. It does not imply that the five aggregates are not real. It simply points towards the five aggregates as being transient and without a self.</p>

<p>Also, please see the <a href="https://www.accesstoinsight.org/tipitaka/sn/sn35/sn35.085.than.html" rel="nofollow noreferrer">Suñña Sutta</a>, which explains this more literally, as the five aggregates being empty of a self.</p>
