The most significant name in the conversation regarding ancient atomic theory is that of Democritus. Born in approximately 460 B.C., Democritus is primarily regarded as a natural philosopher. While he was highly esteemed, Democritus may not have been particularly well liked in his time. English writer E. Brewer records that he is known as The Laughing Philosopher, for his reputation of endlessly mocking human folly. More significantly, his concepts were seen by some as radical, and Bertrand Russell wrote that one of his most well known contemporaries, Plato, suggested that all of Democritus’ books ought to be burned. But as is the case with much of radical thought, history is the most honest judge of truth, and it is history that has remembered Democritus as the father of modern science.
For the sake of clarity, let us briefly summarize Democritus’ atomic theory:
Everything is made up of atoms, which are the smallest tangible unit. These atoms cannot be divided, and they are indestructible. The atoms themselves are constantly moving, and are infinite in number, as well as in variety. The specific kinds of atoms vary in their size and shape. Atoms are separated by empty space, or a void. Atoms can join with one another, forming larger objects. And finally, the more atoms that are clustered together, the heavier that cluster will be. (Russell)
	It bears noting that Democritus was not alone in his formation of this hypothesis, and that he was a student of Leucippus, who is often credited with being the first to suggest the concept of atoms. Later, Epicurus also helped in further developing these ideas. But it is Democritus who is remembered as the most significant contributor to the cause. (Russell)
	The Atomists had a tough case to make. They were certainly not the first ones to ask what everything was made of, and the consequential range of ideas had already been hotly disputed. Before Democritus, Heraclitus and Parmenides each proposed their own unique answer to this question. To properly understand the Atomists’ defense of their ideas we must first take a moment to examine the context in which this debate took place.
	Heraclitus is not regarded as the nicest of men. He was abusively critical of every other philosopher, painting himself in an almost comedic light. For example, he publically stated that Pythagoras lacked understanding, and that Homer deserved to be beaten! (Bakalis) One might conclude then, that his primary contribution to philosophy is suiting. Heraclitus stated (and defended with certainty) that everything is made of fire. Bertrand Russell summarized his idea this way: “Heraclitus considered fire as the most fundamental element. He believed fire gave rise to the other elements and thus to all things.”
	The most relevant aspect of Heraclitus’ argument is that everything is constantly changing. This “fire and flux” theory proved troublesome for many of his contemporaries. Plato, for instance, asked in response, “How can that be a real thing which is never in the same state?” (Cratylus)
