Determining genetic descent among languages

"It is usually supposed that, at one time, at one time there was a
single Indo-European language, the so-called Indo-European
protolanguage, from which all historically attested Indo-European
languages are presumed to descend. This supposition is contradicted
by the fact that, no matter how far we peer back into history, we
always find a multitude of Indo-European-speaking peoples. The idea
of an Indo-European protolanguage is not absurd, but it is not
necessary, and we can do very well without it (Trubetskoy 2001, p. 87)."

"Kretschmer (1896) has rightly emphasized that the only difference
between borrowing and genetic relation is one of chronology. We
recognize as borrowings those words that entered Germanic from Celtic
or Italic and entered Slavic from Germanic only after the Germanic
sound shift [because they do not confirm to certain sound laws…Words
that had taken the same path before the sound shift, on the other
hand, are regarded as belonging to the common stock. Strictly
speaking, we ascribe to the protolanguage all elements that occur in
several branches of Indo-European and for which the direction of
borrowing can no longer be determined. [The same happens in other
language families], (Trubetskoy 2001, pp. 87-88)"

Q: How can the IEL then determine chronology based on the genetic tree
model if the assumption of genetic descent is itself based on chronology?

"There is therefore, no compelling reason for the assumption of a
homogeneous Indo-European protolanguage from which the individual
branches of Indo-European descended. It is equally plausible that the
ancestors of the branches of Indo-European were originally dissimilar
but that over time, through continuous contact, mutual influence, and
loan traffic, they moved significantly closer to each other, without
becoming identical (Trubetskoy 2001, p. 88)."

"But if scholars had only several semi-Romance languages like Albanian
at their disposal and applied to them the comparative method as it is
practiced in Indo-European studies, they would be obliged to
reconstruct a protolanguage for the semi-Romance group as well. In
doing so they would either have to leave the non-Romance elements
unexplained or have to explain them by means of some clever artificial
provisions in the reconstruction of the "proto-language." The picture
would become even more complicated if history had preserved the
descendants of several groups that had begun converging but then
stopped. All of them would share some elements, and comparatives
would have to reconstruct another "protolanguage" from the common
features of their morphology and vocabulary and from the regular sound
correspondences. This protolanguage would not be particularly
difficult to reconstruct, even though it quite obviously never existed

Thus a language family can be the product of divergence, convergence
or a combination of the two (with emphasis on either). There are
virtually no criteria that would indicate unambiguously to which of
the two modes of development a family owes its existence. When we are
dealing with languages so closely related that almost all the elements
of vocabulary and morphology of each are present in all or most of the
other members (allowing for sound correspondences), it is more natural
to assume convergence than divergence (Trubetskoy 2001, p. 89)."

"Be that as it may, the Indo-European family does not consist of very
closely connected branches. Each branch possesses numerous elements
of vocabulary and morphology not matched by the others. In this
respect, Indo-European differs greatly from such families as Turkic,
Semitic and Bantu. Therefore, it is equally probable that the
Indo-European family arose when some originally non-related languages
(the ancestors of the later branches) converged and that the
Indo-European languages developed from a protolanguage by divergence.]

This possibility must always be kept in sight when the Indo-European
problem is addressed[, and every statement about the problem should be
formulated so as to be valid for either assumption: divergence or
convergence.] Since only the hypothesis of a single protolanguage has
been considered until now, the discussion has landed on the wrong
track. Its primary, that is, linguistic, nature has been forgotten.
Prehistoric archaeology, anthropology, and ethnology have been brought
in without any justification. Attempts are made to describe the home,
race, and culture of a supposed Indo-European proto-people that may
never have existed. The Indo-European problem is formulated [by
modern German (and not only German) scholars] in something like the
following way: "Which type of prehistoric pottery must be ascribed to
the Indo-European people?" But scholarship is unable to answer
questions of this kind, so they are moot. Their logic is circular
because the assumption of an Indo-European protopeople with definite
cultural and racial characteristics is untenable. We are chasing a
romantic illusion instead of keeping to the one positive fact at out
disposal—that "Indo-Europeans" a purely LINGUISTIC concept (Trubetskoy
2001, p. 90, emphasis in the original)."

"The only scientifically admissible question is, How and where
(Trubetskoy does not say when) did the Indo-European linguistic
structure arise? And this question should and can be answered by
purely linguistic methods. The answer depends on what we mean by the
INDO-EUROPEAN LINGUSITIC STRUCTURE (Trubetskoy 2001, p. 91, emphasis
in the original, parenthesis added)."

"Languages can this cease to be Indo-European, and they can become
Indo-European. "Indo-European" was born when all six specific
structural features mentioned above first came together in a language
whose vocabulary and morphology displayed a series of regular
correspondences with the later-attested Indo-European languages. It
is not impossible that several languages became Indo-European in this
sense at roughly the same time. [If this is true, then originally
several Indo-European languages existed in a so-called language union,
which later developed into a language family.] We can consider them
today in retrospect only as dialects of the Indo-European
protolanguage, but it is not logically necessary to trace them all
back to one common source. Only geographic contact among these oldest
Indo-European dialects may be assumed with a high degree of certainty
(Trubetskoy 2001, pp. 93-94)."

"Thus, the area in which the oldest Indo-European dialects arose must
be situated somewhere between the areas of Finno-Ugric and the
Caucasian Mediterranean languets. [To be sure, this localization is
rather vague, the more so as we have no idea how far north the
Mediterranean language families spread in the remote past (at present
we find their representatives by the Bay of Biscay and in the northern
Caucasus).] A more precise location cannot be determined. Above all,
we must combat the prejudice that the so-called Indo-European
protolanguage occupied a narrowly defined area (Trubetskoy 2001, p. 95)."

"[There is only one reason that linguists have always considered the
agglutinative languages inferior to the inflectional ones: they
themselves have been native speakers of the later group… I am
inclined, therefore, to think that the Indo-European linguistic
structure arose through a process of outgrowing a primitive inflecting
type, without, however, reaching the more highly developed
agglutinative type (Trubetskoy 2001, pp. 97-98)."

Trubetzkoy, N. S. (2001), Studies in General Linguistics and Language
Structure," Anatoly Liberman (Ed.), translated by Marvin Taylor and
Anatoly Liberman, Durham and London: Duke University Press.

M. Kelkar