Pedacius dioscorides the first herbalist and Aristotle study of material universe.

Dioscorides was a Greek surgeon in the army of Emperor Nero, born in Asia Minor, around AD. 40 he joined the army of Nero so that he could go to different countries and study their flora and fauna. During his military career, he travelled through Italy, Greece, Spain, and France, collecting a vast number of botanical, mineral and biological specimens. Wherever he went, he questioned the natives about the medicinal values and practical uses of the specimens he was medicinal values and practical uses of the specimens he was gathering. The data thus acquired formed the basis of his famous work and Materia Medica.

Pedacius Dioscorides

          As Theophrastus had been the first scientific botanist, Dioscorides was the first to write on medical botany, an applied science. In his work, he has described some six hundred plants and plant products. He offers detailed directions for the gathering and storing of herbs.

          He set the pattern for later works on Materia Medica by a qualitative rather than a botanical classification. That is, he classified plants not based on their families, but under the diseases for which they were cures.

 Materia Medica

   His work was translated into many languages and was followed as an unquestionable authority for more than 1500 years. Up to the 17^th century, the best books on medical botany were simply commentaries on his work. Such an utter dependence upon an authority hampered the progress of medical botany. For centuries, no drug was considered genuine which did not agree with Dioscorides description. Northern European botanists, unaware of the geographical limitation of species, wasted an infinite amount of labour trying to identify the plants of their region with those described by Dioscorides from the Mediterranean area. Thus, the minds of botanists were diverted from the firsthand study of plants.

Study of the material universe

          After his biological studies, Aristotle turned to an examination of the material universe. As a result, he wrote many books like Physics, on the Heavens, Meteorologics*, and Mechanics. But these studies are far inferior to his biological research, because ‘the physical world is too complex for its secrets to be unravelled by a mere inspection’. So he is called a ‘a feeble physicist’. Aristotle, despite his acute power of observation, undertook no experimentation to prove his theories. The long-range effects were disastrous. His physical and astronomical concepts of ions were blindly accepted for centuries.

Aristotle

          Aristotle held that the universe is spherical because the sphere is the most perfect shape. So he held that the earth is also spherical. This conclusion was not based on based on any scientific experimentation but on philosophical reasons or symmetry and equilibrium. He taught that the acceleration of a falling body depends upon its mass. 

This fallacious potion was accepted for two thousand years. While discussing the phenomenon of motion, he held that living beings can move themselves and inert matter cannot do so, unless caused to move by the action of some other body already in motion. Then how to account for a falling stone? Here the ultimate origin remains mysterious, leading him towards theological conclusions.

          In his Meteorologics*, Aristotle treats the region between heaven and earth. He discusses meteors, rain, hail, snow, winds, rivers, the saltiness of the sea, thunder and lightning etc. The range of interests is impressive, though frequently the conclusions are not valid.

* Meteorologic refers to atmospheric phenomena. And weather and weather conditions related.