Republicanism may also refer to the non-ideological scientific approach to politics and governance. As the republican thinker and second president of the United States John Adams stated in the introduction to his famous "Defense of the Constitution," the "science of politics is the science of social happiness" and a republic is the form of government arrived at when the science of politics is appropriately applied to the creation of a rationally designed government. Rather than being ideological, this approach focuses on applying a scientific methodology to the problems of governance through the rigorous study and application of past experience and experimentation in governance. This is the approach that may best be described to apply to republican thinkers such as Niccolò Machiavelli (as evident in his "Discourses on Livy"), John Adams, and James Madison.