of Miletus MacTutor History of Mathematics Thales' Theorem – Math Open Reference (with interactive animation) Thales biography by Charlene Douglass (with extensive bibliography) Thales of Miletus Life, Work and Testimonies by Giannis Stamatellos Thales Fragments 6th-century BC Greek people 6th-century BC philosophers 620s BC births 540s BC deaths Ancient Greek astronomers Ancient Greek geometers Ancient Greek metaphysicians Ancient Greek physicists Ancient Milesians Epistemologists Metaphilosophers Metaphysicians Metaphysics writers Natural philosophers Ontologists Philosophers of ancient Ionia Philosophers of education Philosophers of mathematics Philosophers of mind Philosophers of science Presocratic philosophers Seven Sages of Greece 6th-century BC mathematicians 6th-century BC astronomers