These two viewpoints go back to the first discussions of the nature of Light. the Corpuscular Theory, proposed by Isaac Newton (1642-1727) was that light is made up of tiny particles, or corpuscles. This theory required that light actually travel faster in denser mediums. The Wave Theory, proposed by Christian Huygens (1629-1695) was that light was made up of waves traveling through the "Ether." Rectilinear propagation suggests that light moves in a straight line, but as a wave, light can be diffracted.
Post-Quantum physics considers light to be a wave with some material properties; sometimes it acts like a wave, somtimes like a particle. Exploring the mystery of the Nature of Light actually brought about the Quantum Revolution in Physics in the late 1800's.