"The true law of the race is progress and development. Whenever civilization pauses in the march of conquest, it is overthrown by the barbarian"

William Gilmore Simms' quote, "The real law of the race is development and development. Whenever civilization pauses in the march of conquest, it is toppled by the barbarian", encapsulates a viewpoint on the continuous forward momentum required for the sustainability and improvement of civilization. His option of words shows the 19th-century worldview, in which the suitables of progress and development were synonymous with the expansion, both intellectually and territorially, of dominant cultures.

Simms recommends that development is not simply a natural propensity but an essential guideline or "law" intrinsic to human society. This development includes both tangible development, such as technological and financial advancement, and intangible elements like cultural and intellectual growth. Simms highlights a viewed dichotomy in between civilization and so-called barbarism, suggesting that a lapse in progress welcomes regression or the downfall of a society. Here, "the barbarian" functions as a metaphor for stagnancy or decline, suggesting that societies viewed as less developed or advanced were seen as hazards to recognized civilizations.

The "march of conquest" can be translated as the relentless pursuit of development and growth. During Simms' time, this often referred to colonial and royal conquests, reflecting a Eurocentric view that related civilization with Western improvement. Civilizations that stopped advancing could end up being vulnerable to external influences or internal decay, which he metaphorically describes as being "toppled by the barbarian". This recommends that complacency breeds vulnerability-- if civilizations do not aim to improve and develop, they risk being exceeded or taken apart by those either externally perceived as inferior or historically thought about less advanced.

From a modern-day point of view, Simms' focus on relentless development can be critiqued for its simplistic binary and its disregard of the complexities and ethical measurements of interaction in between cultures. While acknowledging the favorable elements that progress and development can bring, it is equally essential to consider the holistic sustainability of such improvement, appreciating diverse cultural trajectories and values beyond a simply conquest-oriented framework. The quote ultimately challenges societies to reflect on the nature of their progress and the ramifications of their growth methods.