Siddham Ca 𑖓

Ca opens the palatal class, the second of the five, and the order of the classes is what places it there: the sequence runs from the back of the mouth forwards, and the hard palate is the next point after the soft one. It is voiceless and unaspirated, the plainest treatment, in the same relation to its class as ka is to the class before it.

English speakers hear the sound as the ch of church, and the single Latin letter c used to transliterate it invites exactly the wrong reading, since c in English is either a k or an s and never this. The Siddham letter has no such ambiguity, and neither does the Indian analysis, which classifies the sound by where it is made rather than by any resemblance to anything else.

The letter enters conjuncts freely, most visibly with the palatal nasal that closes its own class. In East Asian transcription it has a long history of being matched to whichever consonant the receiving language had nearest to it, which is one of the reasons the Siddham letters were studied there as sounds first and as shapes second: a scholar who wanted to know what a transcribed mantra had originally said needed the letter, not the approximation.

The class it heads is also where the pairing between consonants and vowels becomes visible, since the phoneticians group the vowels i and long i with the palatals on the ground that they are formed at the same place. The letter table and the vowel table are two halves of a single analysis, and this is one of the joins between them.

Chinese has no alphabet, and a Sanskrit word entering a Chinese Buddhist text either had to be translated or had to be written with characters chosen for their sound. Translators did both, in enormous quantity, and the transcription system that resulted is one of the largest bodies of phonetic writing ever produced. It is also the reason the Siddham letters had to travel alongside it.

Transcription loses information in a specific way. Chinese had no equivalent for several Sanskrit distinctions, notably the retroflex series and the voiced aspirates, so different Sanskrit sounds were written with the same character and the difference is simply gone. A reader working back from the characters cannot recover it. Worse, the sound values of the characters themselves shifted over the centuries and differed by region, so a transcription made in one place and period is read differently in another.

That is the practical argument for keeping the script. A dharani transcribed into characters can be chanted, and it was, but it cannot be reconstructed; the Siddham original can be read directly. The Chinese Buddhist canon accordingly carries both, and the transcriptions are now a major source for the historical pronunciation of Chinese itself, since a Sanskrit word of known sound written in characters tells a linguist what those characters sounded like at the time.