As mountains are long before they are conquered, they are likewise long before they are civilized.  Men are softened by intercourse mutually profitable, and instructed by comparing their own notions with those of others.  Thus Caesar found the maritime parts of Britain made less barbarous by their commerce with the Gauls.  Into a barren and rough tract no stranger is brought either by the hope of gain or of pleasure.  The inhabitants having neither commodities for sale, nor money for purchase, seldom visit more polished places, or if they do visit them, seldom return.

It sometimes happens that by conquest, intermixture, or gradual refinement, the cultivated parts of a country change their language.  The mountaineers then become a distinct nation, cut off by dissimilitude of speech from conversation with their neighbours.  Thus in Biscay, the original Cantabrian, and in Dalecarlia, the old Swedish still subsists.  Thus Wales and the Highlands speak the tongue of the first inhabitants of Britain, while the other parts have received first the Saxon, and in some degree afterwards the French, and then formed a third language between them.

That the primitive manners are continued where the primitive language is spoken, no nation will desire me to suppose, for the manners of mountaineers are commonly savage, but they are rather produced by their situation than derived from their ancestors.

Such seems to be the disposition of man, that whatever makes a distinction produces rivalry.  England, before other causes of enmity were found, was disturbed for some centuries by the contests of the northern and southern counties; so that at Oxford, the peace of study could for a long time be preserved only by chusing annually one of the Proctors from each side of the Trent.  A tract intersected by many ridges of mountains, naturally divides its inhabitants into petty nations, which are made by a thousand causes enemies to each other.  Each will exalt its own chiefs, each will boast the valour of its men, or the beauty of its women, and every claim of superiority irritates competition; injuries will sometimes be done, and be more injuriously defended; retaliation will sometimes be attempted, and the debt exacted with too much interest.

In the Highlands it was a law, that if a robber was sheltered from justice, any man of the same clan might be taken in his place.  This was a kind of irregular justice, which, though necessary in savage times, could hardly fail to end in a feud, and a feud once kindled among an idle people with no variety of pursuits to divert their thoughts, burnt on for ages either sullenly glowing in secret mischief, or openly blazing into public violence.  Of the effects of this violent judicature, there are not wanting memorials.  The cave is now to be seen to which one of the Campbells, who had injured the Macdonalds, retired with a body of his own clan.  The Macdonalds required the offender, and being refused, made a fire at the mouth of the cave, by which he and his adherents were suffocated together.