Dual states and paradox
As Leibniz himself symbolizes, this novel is positioned during the transition between the Middle Ages and the scientific era. As urbanization leads to radical evolutions in human government, rapid changes in alchemy and mathematics lead folks like Newton and Leibniz to conclude that human technology is just beginning. The very title of the book is a reminder of this central theme: Quicksilver is Mercury, which in the alchemical science of yesteryear was regarded as a perfect symbol for dual states and paradoxical natures. This is because Mercury is both solid and liquid.
The progress of human history
Through exceptional historical fiction, Quicksilver delivers a case for the inevitable nature of human progress. This is done through dramatic irony as characters play out stories that will likely be known by an educated reader, such as the Great Fires of London, and the events leading to the French Revolution. The progress of time is a kind of slavery that all humans are subject to, and also those experiences of slavery and submission are well-explored in the plot, since one of the protagonist is a slave.
Revolution and conservatism
The novel presents a balance going out of whack. The reader knows the unfortunate outcome of the political imbalances of France in the 1700's is of course the famous French Revolution. This novel makes an argument about the French Revolution showing that there is an inherent risk of (potentially violent) revolution whenever the powerful use conservatism to protect archaic systems of power that still benefit them. This leads to Revolution, which coincides with the theme of human progress in a way noticed in philosophy by Hegel, then Marx.
