the idea of a separation of powers in a government, a concept which was enthusiastically adopted by the authors of the United States Constitution. While the philosophes of the French Enlightenment were not revolutionaries and many were members of the nobility, their ideas played an important part in undermining the legitimacy of the Old Regime and shaping the French Revolution. Francis Hutcheson, a moral philosopher and founding figure of the Scottish Enlightenment, described the utilitarian and consequentialist principle that virtue is that which provides, in his words, "the greatest happiness for the greatest numbers". Much of what is incorporated in the scientific method (the nature of knowledge, evidence, experience, and causation) and some modern attitudes towards the relationship between science and religion were developed by Hutcheson's protégés in Edinburgh: David Hume and Adam Smith. Hume became a major figure in the skeptical philosophical and empiricist traditions of philosophy. Kant tried to reconcile rationalism and religious belief, individual freedom and political authority, as well as map out a view of the public sphere through private and public reason. Kant's work continued to shape German thought and indeed all of European philosophy, well into the 20th century. Mary Wollstonecraft was one of England's earliest feminist philosophers. She argued for a society based on reason and that women as well as men should be treated as rational beings. She is best known for her work A Vindication of the Rights of Woman (1791). Science Science played an important role in Enlightenment discourse and thought. Many Enlightenment writers and thinkers had backgrounds in the sciences and associated scientific advancement with the overthrow of religion and traditional authority in favour of the development of free speech and thought. Scientific progress during the Enlightenment included the discovery of carbon dioxide (fixed air) by chemist Joseph Black, the argument for deep time by geologist James Hutton, and the invention of the condensing steam engine by James Watt. The experiments of Antoine Lavoisier were used to create the first modern chemical plants in Paris, and the experiments of the Montgolfier brothers enabled them to launch the first manned flight in a hot air balloon in 1783. The wide-ranging contributions to mathematics of Leonhard Euler included major results in analysis, number theory, topology, combinatorics, graph theory, algebra, and geometry (among other fields). In applied mathematics, he made fundamental contributions to mechanics, hydraulics, acoustics, optics, and astronomy. Broadly speaking, Enlightenment