摘要：The study is an investigation of the origins of psychophysics and experimental psychology. According to historians of psychology, Francis Bacon had the most crucial influence in the history of the experimental method, because he emphasized the importance of induction, skepticism, quantification, and observation. The present study, however, attempts to show that Ibn al-Haytham laid the foundations of the above aspects of the experimental method. Furthermore, a number of historians of psychology believe that Fechner was the founder of psychophysics with his application “Filements of Psychophysics” in 1860. This study shows that in the eleventh century, Ibn al-Haytham made an original contribution to the study of vision, wherein his psychophysics borrowed its structure from physics and its spirit from psychology. Several aspects of visual perception were investigated by him, including sensation (which occupies a central place in psychophysics), variations in sensitivity, perception of colors. sensation of touch, perception of darkness, the psychological explanation of moon illusion, and binocular vision. This study presents five experiments by Ibn al-Haytham regarding the errors of vision, which is called in contemporary psychology “visual illusion.” These experiments have been applied and verified in Bahrain from both the physical and psychological perspectives. Finally, the study concludes that Ibn al-Haytham deserves the title “founder” of psychophysics as wellp the “founder” of experimental psychology. In this respect. Kitab ul-Manazir by Ibn al-Haytham. which appeared in the fmt half of the eleventh century, and not the “Elements of Psychophysics” by Fechner, which was published in the nineteenth century, marks the official “founding” of psychology, because it provides not only new concepts and theories but new methods of measurement in psychology.
