In a clear instance of overstatement, or hyperbole, Burke begins his discussion of the French Revolution by saying:
All circumstances taken together, the French revolution is the most astonishing that has hitherto happened in the world.
Obviously, the French Revolution cannot be the "most astonishing" thing that has ever happened in the history of the world. While revolutions do not happen every day, there have been revolutions before, both in England's own history (as Burke acknowledges) and on the global stage. In fact, the American Revolution concluded in 1783, only seven years prior to the publication of Reflections on the Revolution in France.
Rather than attempting to make an earnest and factual statement about the French Revolution, Burke employs this hyperbole to emphasize the extremity of his personal response to the uprising, a political phenomenon he describes as a "strange chaos of levity and ferocity." As Burke employs it, the word "astonishing" conveys a range of emotions. The first is that of surprise: clearly, despite the revolutionary air of this time period and the political treatises of his contemporaries, Burke did not anticipate the French Revolution happening as it did. However, this surprise takes a back seat to feelings of shock, outrage, and scandal, all of which are implied through Burke's word choice.