He's saying there is only one fundamental force, rather than 4. Weak and strong nuclear forces and gravity are all attributes of magnetism and electricity. There is no 'spacetime'. That is what is used to try and explain gravity and the bending of light.

This is exactly as have I come to understand it, completing the puzzle by incorporating the dielectric field as the only real field of which magnetism is the attribute.

If you're interested, I think it was quite a good discussion to listen to: