Ibn al-Haytham



Ibn al-Haytham was the first person ever to set down the rules of science. Ibn al-Haytham (full name Abu Ali al-Hasan ibn al-Hasan ibn al-Haytham; commonly known as ibn al-Haytham, Ali al-Hasan, or in older texts as the Latinized "Alhazen"; Arabic: أبو علي، الحسن بن الحسن بن الهيثم‎‎) (c. 965 – c. 1040 CE) was a scientist from the Islamic Golden Age. Despite being virtually unknown in the modern West, he was an extremely important figure in the history and philosophy of science, as his experiments in optics were essentially the first step in the development of what would one day be called the scientific method.

Book of Optics
His magnum opus was the Book of Optics (Kitab al-Manazir; Arabic: كتاب المناظر), a compendium of optical knowledge famous for, among other things, disproving the (the idea that our eyes project light onto objects rather than receive it, which was considered possible at the time). What is most impressive about this was his emphasis on rigorous experiment, rather than appeals to argumentation or reason. Al-Haytham was the first to describe a theory, make a prediction based on that theory, design an experiment which could refute it, and then carry out the experiment and successfully disprove it. In other words, he was essentially the first known user of the scientific method, although the particulars would not be laid out until Francis Bacon some centuries later.

Scientific views
The following quote from his work Doubts Concerning Ptolemy illustrates this perspective nicely: