of thinking and might have constructed the first teleological argument "it would not be possible without Intellection for it so to be divided up that it has the measures of all things — of winter and summer and night and day and rains and winds and fair weather. The other things, too, if one wishes to consider them, one would find disposed of in the best possible way." While some pre-Socratics were trying to find alternatives to divinity, others were setting the foundation of explaining the universe in terms of teleology and intelligent design by a divine force. Medicine Prior to the pre-Socratics, health and illness were thought to be governed by gods. Pre-Socratic philosophy and medicine advanced in parallel, with medicine as a part of philosophy and vice versa. It was Hippocrates (often hailed as the father of medicine) who separated – but not completely – the two domains. Physicians incorporated pre-Socratic philosophical ideas about the nature of the world in their theoretical framework, blurring the border between the two domains. An example is the study of epilepsy, which in popular religion was thought to be a divine intervention to human life, but Hippocrates' school attributed it to nature, just as Milesian rationalism demythologized other natural phenomena such as earthquakes. The systematic study of anatomy, physiology, and illnesses led to the discovery of cause-effect relations and a more sophisticated terminology and understanding of the diseases that ultimately yielded rational science. Cosmology The pre-Socratics were the first to attempt to provide reductive explanations for a plethora of natural phenomena. Firstly, they were preoccupied with the mystery of the cosmic matter—what was the basic substance of the universe? Anaximander suggested apeiron (limitless), which hints, as Aristotle analyzed, there is no beginning and no end to it, both chronologically and within the space. Anaximenes placed aêr (air) as the primary principle, probably after realizing the importance of air to life and/or the need to explain various observable changes. Heraclitus, also seeking to address the issue of the ever changing world, placed fire as the primary principle of the universe, that transforms to water and earth to produce the universe. Ever-transforming nature is summarized by Heraclitus' axiom panta rhei (everything is in a state of flux). Parmenides suggested two ever-lasting primary building blocs, night and day, which together form the universe. Empedocles increased the building blocks to four and named them roots, while