The term ‘Empty’ or ‘Null’ as used in English translations of Śūnyatha and Śūnya originate directly from the vocabulary of Classical Logic, [Logic’s ‘Empty Class’] as does the word ‘Form’ as used in the Heart Sutra.
But they were flailing around for an equivalent choice for the term Nāmarūpa [Rūpa; in fact by this time its interpretation in the Sanskrit itself had become entirely flaccid.]
Then the Translators noticed the English word ‘Form’ which happened to be part of the extended vocabulary of Classical Logic. It had a nice ring to it and the meaning appeared very close to the word Nāmarūpam.
And so they went with ‘Form’, a palliative compromise. [The word first appears in Plato’s ‘Theory of Forms’ which is probably where it was noticed. The English word ‘Idea’ originates here.]
But Nāmarūpa is not exactly ‘Form’. And the two words are not perfect translation matches. And to see where and how they are different can make all the difference.
Nāmarūpa has a seriously slippery feature to it: Self-Reference.
‘Form’ as commonly used in Classical Logic is: ‘Something that is marked, has taken shape’. A line, a curve, a color, a smell, a melody, a scratch. Logic comes alive, is operative, only in the abstract, only in the world of Form.
But Nāmarūpa does not exactly overlap with the ‘Form’ as defined by the Logician. Nāmarūpa like Form, is ‘Something that is marked, has taken shape’. But Nāmarūpa, unlike the Logician’s Form, an ‘Objective’ presence, includes within its domain all ‘Subjective’ presence’ as well.
Feeling is Nāmarūpa, a mental-image is Nāmarūpa, internal-dialogue is Nāmarūpa. All that you see with your eyes closed or hear with your ears plugged are part of Nāmarūpa. If you can name it, mark it, express it, put a metaphorical finger on it, it is part of Nāmarūpa.
All references to Nāmarūpa are already contained in Nāmarūpa as are all thoughts you have in response to it.
If you slip on its self-referential feature you will confound Nāmarūpa with Awareness, Consciousness, Presence, Everything and other such heavy concepts, and find yourself thrashing around on the tails of the Self-Loop.
The texts themselves carry numerous and often conflicting versions of Nāmarūpa a term that predates the Sūtra. The version used here is as that used in the Heart Sūtra. The most popular one includes Vasanas, hold-over mental constructions from the past and there are many definitions with such variations.
It’s important not to fall into the Academic Trap of getting stuck on words. If you find any of the above confusing, ignore it and get back on the Meditation Mat.
The material can be expanded substantially if one were to go into the later evolution of Platonic Form and the Academic Philosopher’s love of ‘Universals’. But I shall stop here.
No guru, fee-speaker or book-writer I have met is aware of this connect as the source of the translated terms, which might explain their wildly creative interpretations.
It partly explains why they keep talking about the emptiness of tables and trees instead of what’s doing the observing, making the claim about the tables and trees.