Newton's Corpuscular theory

In optics, the corpuscular theory of light, arguably set forward by Pierre Gassendi and Thomas Hobbes states that light is made up of small discrete particles called "corpuscles" (little particles) which travel in a straight line with a finite velocity and possess impetus. This was based on an alternate description of atomism of the time period. And it is supported by Planks Quantum Theory of Light.

Mechanical Philosophy

In the early 17th century, natural philosophers were seeking new information to replace Aristotelianism that had been popular for centuries. Various European philosophers adopted what came to be known as mechanical philosophy sometime between around 1610 to 1650, which described the universe and its contents as a kind of large-scale mechanism, a philosophy that explained the universe is made with matter and motion.^[1] This mechanical philosophy was based on Epicureanism, and the work of Leucippus and his pupil Democritus and their atomism, in which everything in the universe, including a person's body, mind, soul and even thoughts, was made of atoms; very small particles of moving matter. During the early part of the 17th century, the atomistic portion of mechanical philosophy was largely developed by Gassendi, René Descartes and other atomists.

Sir Isaac Newton

The corpuscular theory was largely developed by Sir Isaac Newton. Newton's theory remained in force for more than 100 years and took precedence over Huygens' wave front theory, partly because of Newton’s great prestige. When the corpuscular theory failed to adequately explain the diffraction, interference and polarization of light it was abandoned in favour of Huygens' wave theory.To some extent, Newton's corpuscular (particle) theory of light re-emerged in the 20th century, as light phenomenon is currently explained as particle and wave.

Newton's corpuscular theory was an elaboration of his view of reality as interactions of material points through forces. Note Albert Einstein's description of Newton's conception of physical reality:

[Newton's] physical reality is characterised by concepts of space, time, the material point and force (interaction between material points). Physical events are to be thought of as movements according to law of material points in space. The material point is the only representative of reality in so far as it is subject to change. The concept of the material point is obviously due to observable bodies; one conceived of the material point on the analogy of movable bodies by omitting characteristics of extension, form, spatial locality, and all their 'inner' qualities, retaining only inertia, translation, and the additional concept of force.

1. Every source of light emits large numbers of tiny particles known as corpuscles in a medium surrounding the source.
2. These corpuscles are perfectly elastic, rigid, and weightless.