How can you say you know causality doesn't exist, either? Everything you "know" you found through induction.
Knowledge and learning, all processes, are still the product of physical mechanisms whether or not we choose to apply a word like "knowledge" or "induction" to a common theme. Photons radiating from my computer screen are refracted through my lenses, trigger the rods and cones in my retina, induce neurotransmission, etc, etc and eventually we take a step back, look at the big picture which is that I've learned something by reading the screen.
It all comes down to physical processes. Applying a descriptor like "cause" has only to do with how we logically organize them.
But there is no argument in the world that doesn't eventually become circular, so I'm not going to contend to you that I somehow can prove any of this. What should be kept in mind is that something that exists only metaphysically is probably just a human cognitive label for a set of physical processes that share a theme.