La and the Pairing of Vowel and Semivowel

The four pairings that link a semivowel to a vowel are among the most elegant things in the Indian analysis, and they explain why the vocalic liquids were classed as vowels in the first place. If ya is the consonantal counterpart of i and va of u, then a system that recognises those pairs must ask what the counterparts of ra and la are, and the answer is the vocalic r and vocalic l. The rare letters at the head of the chart exist because the pattern demands them. Once that is seen, the whole arrangement of the varnamala reads as a single argument rather than as two lists joined together, and the rare vowels stop looking like curiosities.

For Ranjana the point is not decorative. The script inherited the argument along with the letters, and its charts, its recitation and its teaching carry all of it, which is why a Ranjana alphabet has fourteen independent vowels rather than the six a European reader would predict and thirty three consonants rather than a number fitted to any particular language. It also shows why the chart cannot be shortened without damage. Removing the rare vowels would leave the semivowel pairings with nothing to pair against, and the argument that holds the two halves of the order together would no longer be visible on the page.