I think you'd have to consider the "biggies", Robert the Bruce and William Wallace, even though they predate the Enlightenment.

Also, although I know it's cheating the question a bit, instead of a specific individual how about the generic "Scottish Soldier"? Scottish Servicemen had a huge impact on the culture and traditions of Scotland (saved the kilt from oblivion, even?) as well as worldwide impact through service in far-flung reaches of the Empire...

Cordially,

David