user-1: Might it be true that emptiness can be conceived of as the one taste of mind: that the world of mind has only one reality which is everywhere and always the same, unchanging.
Who (which groups or individuals) say so?
And: what reasons are there to believe it is a correct charaterisation of mind?

user111: If one focuses on the emptiness of things, it will be the object of the mind at that time. Those(non Buddhists) who attain the Ākiṃcanyāyatana(7th Jhana) could get the false view that sphere of Nothingness is unchanging and permanent. But it isn't. 

user715: I think such experiential truths should not be intellectualised. Any intellectual stance - of permanence or impermanence will be outside of non-dual reality. 
Silence is the right answer. cf. Vimalakirti sutra (Wikipedia).

Vimalakīrti remains silent while discussing the subject of emptiness
  with an assembly of bodhisattvas. The bodhisattvas give a variety of
  answers on the question what non-duality is. Manjusri is the last
  bodhisattva to answer, and says that "by giving an explanation they
  have already fallen into dualism". Vimalakirti, in his turn, answers
  with silence.

p.s. I didn't downvote, I don't object to the question.

-1: <p><em>Might</em> it be true that emptiness can be conceived of as the one taste of mind: that the world of mind has only one reality which is everywhere and always the same, unchanging.</p>

<p>Who (which groups or individuals) say so?</p>

<p>And: what <strong>reasons</strong> are there to believe it is a correct charaterisation of mind?</p>
 111: <p>If one focuses on the emptiness of things, it will be the object of the mind at that time. Those(non Buddhists) who attain the Ākiṃcanyāyatana(7th Jhana) could get the false view that sphere of Nothingness is unchanging and permanent. But it isn't. </p>
 715: <p>I think such experiential truths should not be intellectualised. Any intellectual stance - of permanence or impermanence will be outside of non-dual reality. </p>

<p>Silence is the right answer. cf. <a href="https://en.wikipedia.org/wiki/Vimalakirti_Sutra#Use_of_silence" rel="nofollow">Vimalakirti sutra</a> (Wikipedia).</p>

<blockquote>
  <p>Vimalakīrti remains silent while discussing the subject of emptiness
  with an assembly of bodhisattvas. The bodhisattvas give a variety of
  answers on the question what non-duality is. Manjusri is the last
  bodhisattva to answer, and says that "by giving an explanation they
  have already fallen into dualism". Vimalakirti, in his turn, answers
  with silence.</p>
</blockquote>

<p>p.s. I didn't downvote, I don't object to the question.</p>
