Originally posted by Albanactus
Anyways, whether Alexander Warrack has an MA, an M.Phil., a PhD or a special award offered by God himself, still doesn't mean English speakers had half the "Scottish" population by any time before 1600.
Although given that he has an MA in linguistics and you don't you might forgive me if I tend to attach greater credibility to his arguments rather than yours as I would assume an individual with such a qualification might have taken the time to be fully informed of the matter he is discussing.
English is quite clearly in use throughout eastern and central Scotland by 1350 and earlier because of the spread of the burgh; but that means no more than the use of German throughout the burghs of Poland and Mazovia, or the use of French amongst the aristocracy of England and Scotland.
That argument has one flaw-it depends upon the spread of Inglis as being solely the result of the growth in burghs in lowland Scotland whereas in fact that is clearly not the case.Inglis spread throughout the middle ages as the Scottish crown and nobility consolidated their grip on the Lothians,Fife and as far north as Moray and as their influence spread so did their system of values and their language-Inglis which later became Scots.So we're not dealing specifically with a growth in towns and burghs we're talking about a culture and system of values gradually supplanting the existing Gaelic culture and outwith the area of the highlands that process was pretty much complete by the early modern period.
It's one of the ironic facts of history that there is much more evidence for the use of French in pre-War of Independence Scotland than English,
Absence of evidence isn't evidence of absence.Obviously textual evidence from medieval Scotland is rare but it isn't non existent as there are documents such as charters,royal warrants etc. from the period showing that Inglis was in widespread usage throughout the lowlands.
yet until recently no-one ever took any notice, anxious to focus on the badly testified, yet obviously Pre-Ordained, Inevitable Onward Triumphal March of English ...
Whenever I debate this question on these boards I'm always aware that I'm a historian solely interested in facts and evidence debating with people who tend to take a subjective view of Gaelic and its history.There was never any "pre-ordained,inevitable,onward,triumphal march of English".There was a gradual process of change whereby English spread and eventually developed into Scots a tongue which is every bit as much a part of our nation's culture and heritage as Gaelic is.
magnify the flimsy evidence out of all proportion (whilst ignoring contrary evidence) and back-date it as far as possible. 
If you wanna know the real boundary of the English language by the Wars of Independence, the only thing close to a guide I've ever come across is Barrow's "Ingilston map" in The Kingdom of the Scots .. which incidentally also suggests most Anglo-Gaelic population movement was focused on a failed attempt to anglicize Galloway.
To be fair I haven't magnified any evidence out of proportion-I've only cited the objective and unbiased views of a professional linguist and one contemporary source which supports my argument.If the only source you have ever come across concerning the boundary of English by the wars of indepence is Barrow's "Ingliston map" I suggest you pay a visit to your local library where you may find ample evidence of contemporary texts confirming its widespread usage throughout the lowlands throughout the entirety of the middle ages and early modern period.