why are Baltic not considered Slavic?

[Christabel]

Did they derive from a common balto-slavic language?

[Marulus]

Why should they be considered Slavic? Baltic and Slavic are two distinct language families. However, they have some common characteristics that set them apart from other families of the Indo-European tree. Even some common words. There is an (unproven) hypothesis that both famnily might have descended from certain older family.

[Ostrogorski]

Because Balts are not Slavs. It couldn't be simpler...

[Breogan]

Originally Posted by Christabel

Did they derive from a common balto-slavic language?

Balto-Slavic languages - Wikipedia, the free encyclopedia

[Truth-Finder]

Originally Posted by Christabel

Did they derive from a common balto-slavic language?

They may be derived from a common PIE sub-branch but they evolved in such a way that today the distance between both two is greater between the indian and the iranian languages.

keltic and italic languages seem to have derived from a same sub branch aswell but they differentiated later in such a way that none today would considere keltic languages as italic

[M.R.]

Even if they were - who gives a damn?

[Gromoljut]

Originally Posted by M.R.

Even if they were - who gives a damn?

That is utter ignorance.

[Gromoljut]

To anyone seeking the discussion that ensued - it was moved here.

Also, my answer to Christabel's opening question of this thread was moved there. I quote:

Originally Posted by Gromoljut

The question [...] is clearly aimed at the linguistic aspect of baltic and slavic - why are they considered separate?
To answer this question without further delay:
Slavic and baltic are two language families which show a greater degree of similarity between each other than they do to other language families. This allowed for two different theories about the origin of this situation:
a) Slavs and balts branched off their ancestor language in union, which would make their evolution look like this:
(protolanguage) => balto-slavic => (1)baltic, (2)slavic => (1)old prussian, latvian, ..., (2)old east slavic, old west slavic, ....
b) Slavs and balts branched off separately (still, out of geographic reasons, being extremely similar), and aquired many of their common features through influencing each other. Their evolution in this case:
(protolanguage) => (1)prebaltic ~ (2)preslavic => (1)protobaltic, (2)protoslavic => (1)old prussian, latvian, ..., (2)old east slavic, old west slavic, ....
The language families in question are extremely similar in vocabulary. Most divergence of the modern word inventory of languages of both families is easily explained by as few as 5 or 6 phonetic proceses : palatalisation (all three), nasalisation, iotation, monophtongisation - occured in slavic, but not in baltic, satemisation - results of the satemisation show a contrast of slavic : latvian : lithuanian, but they most probably went through a common stage (I know nothing of the extinct baltic tongues, sorry), the ruki sound law (a contrast of slavic : baltic). There is a considerable overlap in accentology of the two families; the morphology differs more between both families, but less compared to other families.