It's very important to understand what matter is supposed to be. Here we'll explain how people came up with the idea of matter and why, looking back on it, we don't need it to explain anything. There are better ways to explain the same physical features matter was invented to explain. There's not one single physical quality we traditionally ascribe to "matter" that cannot be accounted for in terms of number, geometry, and natural laws. Observed quantities of mass, shape, weight, volume, and solidity (the markers of physicality) can all be explained more simply by an evolution of perceptual schemas. It was originally thought that a theoretical 'something' being the cause of our sensible quality experience would help explain why we all experience roughly the same thing. But no explanation of how this 'something' actually caused our sensible quality experience was forthcoming -- nor was it clear there would ever be such an explanation. It ended up being a kind of vestigial piece of our old theories that never worked. Matter itself thus became the thing to explain, and it defied explanation. This series of 20 videos on "Metaphysics" was originally recorded from June 1 - Oct. 4, 2023.