Sometimes you can find some “gaps” in the theories or even in the progress of these theories involved in your research. They become an anecdote about that theory. I’ve found an anecdote about the development of Chomsky’s theory, Generative Grammar, linked with my research. Perhaps the scholars know it – I am not sure.
There is one famous linguistic classification in Chomsky’s theory, “deep structure and surface structure”, which fell down in the last development of the theory known as Minimalist Program, that could be adjusted years before and have put the theory in advance in a way that is dealt today. In 1965, Noam Chomsky wrote in the preface of his book Aspects of the Theory of Syntax that Pāṇini’s grammar (Aṣṭādhyāyī) is a “generative grammar, in essentially the contemporary sense of this term”. If someone developing a new theory bumps into a work that delineates the same theory, he should study carefully this work before giving a next step. It seems that Chomsky never did it in respect of Pāṇini’s grammar, which made him to lose time in the discovery of some details of the new concept of his theory.
Concerning deep and surface structures, or syntactic-semantic relations, in 1969, Paul Kiparsky and J.F. Staal wrote the paper Syntactic and Semantic Relations in Pāṇini, where they compare the kāraka’s system with those deep and surface structures, their conclusion is:
“It seems that the general form of Pāṇini’s syntatic rules and levels is in fact rather difference from those of a generative grammar. In the theory of Chomsky, deep structures and surface structures have the same formal properties. Both are represented by trees with labeled nodes and ordered branches. The set of deep structure categories (Sentence, Noun Phrase, Verb, Phrase, etc.) is a subset (perhaps a proper subset) of the set of surface structure categories. For Pāṇini, on the other hand, each category belongs to one and only one level.”
And before they noted:
“For Pāṇini […] the constituents of a sentence are all on a par, with no further hierarchical structure.”
It was only in 1995 that Noam Chomsky’s paper Bare Phrase Structure brought in the same conclusions seen in Pāṇini and noticed by Kiparsky and Staal in 1969, so twenty six years later. In the paper is noted:
“A linguistic expression of L is at least a pair (π, λ) of this sort and under minimalist assumpions, at most such a pair, meaning that there are no ‘levels of linguistics structure’ apart from the two interface levels PF and LF; specifically, no levels of D-structure or S-structure.”
OBS: the terms D-structure and S-structure are respectively deep and surface structures, the terms PF and LF are phonetic form and logical form.
All the changings of the last part of the theory MP were conceived in respect of the goal “to explain how it arises in the mind of the speaker the problems of descriptive and explanatory adequacy” (1995); but as regards the changings, MP also brought in a new ‘computational system’, in which all the phrase structure rules and X-bar theory was criticized and ‘rewritten’, what was responsible for some changings in the theory of context-free languages and grammars, part of the area of NLP.
For Pāṇini, a structure could never be seen as deep and surface, but on pairs in one unique level. What makes the structure (syntax) much more “computable”. Twenty six years of delay, therefore, could be very useful for the development of Chomsky’s theory, in the end all area of natural language processing could be affected.
But more than this, in the paper (1995), Chomsky ensures:
“The basic assumption of the P&P model [Principles and Parameters] is that languages have no rules at all in anything like the traditional sense [of his theory] and no grammatical constructions except as taxonomic artifacts”
However, Kiparsky and Staal (1969) noted:
“It has been said that Pāṇini’s method was taxonomic […], the kāraka theory suggests not only that such statements are untrue, but also that Pāṇini’s treatment of syntax and semantics presents analogies to various aspects of several modern linguistic theories, whithout being directly identifable with any of them”.
What Chomsky calls Principles and Parameters model is exactly what Pāṇini calls Sāmānya (general) and Viśeṣa (particular) and all his grammar is delineated with them. If Chomsky had studied the Aṣṭādhyāyī in 1965, maybe he could advance his theory and avoid some mistakes the theory has.
PS: If you want to read a very good critical paper about Chomsky’s Minimalist Program, read The Structure of Unscientific Revolutions, Shalom Lappin, Robert D. Levine and David E. Johnson, 2000 (on web). The papers I quoted here can be found on web.