also adding Love and Strife, to serve as the driving force for the roots to mingle. Anaxagoras extended even more the plurality of Empedocles, claiming everything is in everything, myriads of substances were mixing among each other except one, Nous (mind) that orchestrates everything—but did not attribute divine characteristics to Nous. Leucippus and Democritus asserted the universe consists of atoms and void, while the motion of atoms is responsible for the changes we observe. Rationalism, observation and the beginning of scientific thought The pre-Socratic intellectual revolution is widely considered to have been the first step towards liberation of the human mind from the mythical world and initiated a march towards reason and scientific thought that yielded modern western philosophy and science. The pre-Socratics sought to understand the various aspects of nature by means of rationalism, observations, and offering explanations that could be deemed as scientific, giving birth to what became Western rationalism. Thales was the first to seek for a unitary arche of the world. Whether arche meant the beginning, the origin, the main principle or the basic element is unclear, but was the first attempt to reduce the explanations of the universe to a single cause, based on reason and not guided by any sort of divinity. Anaximander offered the principle of sufficient reason, a revolutionary argument that would also yield the principle that nothing comes out of nothing. Most of pre-Socratics seemed indifferent to the concept of teleology, especially the Atomists who fiercely rejected the idea. According to them, the various phenomena were the consequence of the motion of atoms without any purpose. Xenophanes also advanced a critique of anthropomorphic religion by highlighting in a rational way the inconsistency of depictions of the gods in Greek popular religion. Undoubtedly, pre-Socratics paved the way towards science, but whether what they did could constitute science is a matter of debate. Thales had offered the first account of a reduction and a generalization, a significant milestone towards scientific thought. Other pre-Socratics also sought to answer the question of arche, offering various answers, but the first step towards scientific thought was already taken. Philosopher Karl Popper, in his seminal work Back to Presocratics (1958) traces the roots of modern science (and the West) to the early Greek philosophers. He writes: "There can be little doubt that the Greek tradition of philosophical criticism had its main source in Ionia ... It thus leads