Why did Voltaire describe Scotland as a source of rules of taste in the arts?

In 1762, Voltaire famously remarked that Scotland had become the source of "rules of taste in all the arts, from epic poetry to gardening" because of the extraordinary intellectual and cultural output known as the Scottish Enlightenment.

During the second half of the 18th century, Edinburgh emerged as a "hotbed of genius," where a vibrant community of thinkers, writers, and artists engaged in rigorous intellectual disputation. This movement was characterized by a distinct focus on empirical methods and the application of "useful knowledge" across diverse fields.12

The "rules of taste" Voltaire observed were reflected in the era's significant advancements in:
* Literature and Belles Lettres: Led by figures like Hugh Blair, who held the first chair of rhetoric at the University of Edinburgh, and poets such as Robert Burns.1
* Architecture: Exemplified by the Classical proportions of Edinburgh’s New Town and the work of Robert Adam.12
* Portraiture: Driven by artists like Allan Ramsay and Henry Raeburn.1