In the mean time another sect of philosophers arose, who like the Ionians, sought to explain nature, but by a different method. Anaximander, born B.C. 610, was one of the original mathematicians of Greece, yet, like Pythagoras and Thales, speculated on the beginning of things. His principle was that the _Infinite_ is the origin of all things. He used the word [Greek: archae] to denote the material out of which all things were formed, as the everlasting and divine. [Footnote: Arist., _Phy_., iii. 4.] The idea of elevating an abstraction into a great first cause is certainly puerile, nor is it easy to understand his meaning, other than that the abstract has a higher significance than the concrete. The speculations of Thales tended toward discovering the material constitution of the universe, upon an _induction_ from observed facts, and thus made water to be the origin of all things. Anaximander, accustomed to view things in the abstract, could not accept so concrete a thing as water; his speculations tended toward mathematics, to the science of pure _deduction_. The primary being is a unity, one in all, comprising within itself the multiplicity of elements from which all mundane things are composed. It is only in infinity that the perpetual changes of things can take place. [Footnote: Diog. Laert., i. 119; Cicero, _Tus. Qu._, i. 16; Tennemann, p. 1, ch. i. Sec. 86.] This original but obscure thinker prepared the way for Pythagoras. [Sidenote: Pythagoras--Number the essence of things.] [Sidenote: Order and harmony in nature.]