Although this great founder of modern science could not anticipate the findings of his intellectual descendants, his eloquent declaration captures the essence of the most important organizational principle of rationalist thinking. A glass of wine is a complex system that operates according to the basic principles of the universe. The rationalist believes that everything in the universe is driven by principles, that nothing happens by accident, and that there are no special cases. If you can understand the fundamental principles, then you need not learn anything else, for everything is derivable from those principles. This concept is most easily and clearly applied in physics.
Physicists believe that a handful of fundamental principles control all physical phenomena.
One of the goals that physicists pursue is the reduction of the number of principles held to be fundamental. A particularly pleasing example of this came when magnetism, which had been thought to be a fundamental force, was found to be nothing more than the electric force operating under relativistic conditions. In other words, you can derive all the rules of magnetic fields from special relativity and the rules for electric fields. Particularists feel that universal principles are all well and good, but applying them to the real world is a mistake, because the real world is too complex to submit to such simplistic approaches. Particularists see the world as a messy place, a clutter of special cases that defy rational analysis.