Roger Bacon, a 13th-century Oxford-educated Franciscan friar, wasn't really the first scientist. But he was an influential advocate of the methodology we call modern science.
In the author's view, Bacon met and exceeded four standards that together define a true scientist: He believed in mathematics as the foundation for science; he was open to information without bias; he understood the need to communicate his findings; and he realized the importance of experimentation. Arab and Muslim scientists like al-Kindi and Alhazen qualified as true scientists in this sense. But Bacon advanced this methodology in Europe, setting the stage for figures like Galileo and Newton.
Roger Bacon was a polymath, a genius in many fields - physics (including optics), mathematics, early chemistry, geography, languages, even music. Much of his scientific training was based on the Arab masters, whom he read in Latin translation. He was fascinated by applied science - technology - and he envisioned an array of mechanical inventions of the future, including ornithopters and other flying machines, that influenced Leonardo Da Vinci three centuries later.
Bacon's genius as a scientist actually cost him his reputation. After his death, legends arose portraying him as a great magician - a label he would have angrily rejected. In time, he was marginalized and forgotten.
Bacon's reputation as a scientist was revived in the Victorian era, but only partially. He still stands in the shadow of a more famous Bacon, Sir Francis, the Elizabethan often identified with the scientific method. Yet in many ways, Roger was much more influential. Not only did he recognize the great value of Arab science for ongoing research - for example, the optics of Alhazen, which he expanded upon - but he brought new insights to these endeavors and assured their dissemination among Europe's scientific community.