The artist who wrote a treatise in the 18th-century (1753) called, "The Analysis of Beauty" was William Hogarth. "The Analysis of Beauty" is a book which describes Hogarth's theories of visual beauty and grace in a manner accessible to the common person of his day.

Prominent among Hogarth's ideas of beauty was the theory of the Line of Beauty. It is an S-shaped (serpentine) curved line that excites the attention of the viewer and evokes liveliness and movement. "The Analysis of Beauty" formed the intellectual centerpiece of what Ernst Gombrich, a popular historian, described as Hogarth's "grim campaign against those with only fashionable taste". Hogarth himself described his actions as his "War with the Connoisseurs".

In Hogarth's book, he implements six principles that independently affect beauty. He states that the principles have an effect, but he is not determinate on their specific influence. His six principles concern fitness, variety, regularity, simplicity, Intricacy, and quantity, which is associated with the notion of the sublime. Hogarth, with his interest in making art and visual aesthetics accessible to the public at large, through works like "The Analysis of Beauty" believed people would learn to appreciate true beauty when they found it.

More Info: en.wikipedia.org