Empedocles of Acragas (or Akragas or Agrigentum), fl. mid-5th BC. One of the greatest of the Greek Presocratic thinkers, he put forth a view of the world as composed of four elements, earth, air, fire and water, whose relation to one another was governed by the principles of Love and Strife.
He is generally considered either a "qualitative pluralist" or an Eleatic thinker.
Internet Encyclopedia of Philosophy article. Summarizes this early Greek thinker's thought and presents what is known about his life. www.utm.edu/research/iep/e/empedocl.htm
Includes the Leonard translation of the Empedocles' fragments alongside the original Greek, as well as the Life of Empedocles from Diogenes Laertius. classicpersuasion.org/pw/empedocles
A 2000 paper by Simon Trepanier. An intensive study of this, the longest and most illuminating of Empedocles' fragments. www.humboldt.edu/~essays/paper1.html
Short article by Stephen Stenudd reviewing the cosmological aspects of Empedocles' writings, and Aristotle's reaction to them. www.stenudd.com/myth/greek/empedocles.htm