Humanism was particularly important from the seventeenth century onwards, in what is called “the Enlightenment”. Famous names associated with this period would include Montaigne, Voltaire and Rousseau, as well as the Founding Fathers of the United States. But the best theorist for our purposes is…
Hume was a philosopher in the 18th century, and a leading figure in the Scottish Enlightenment. He developed a humanist philosophy that foreshadowed much modern psychology – by, for example, emphasising the role of emotion in guiding behaviour, and by doing away with the notion of a substantial soul. He is famous, in addition, for introducing the so-called “Is-Ought” distinction to philosophy; a distinction that still provokes heated argument among philosophers, and which has spawned innumerable books, conferences and drunken fights.
All in all, a guiding light of secular Humanism.