Does Nagarjuna's Middle Treatise 24:18 teach real knowledge?

I like this verse, it is simply stated, and I like simple statements that can be made into something, or understood as, important. But I'm totally unsure how to make sense of its four (famous) components! I probably think that "emptiness" means no causation, the idea that conditioned (caused) things don't exist in **reality**: that any *supposed* knowledge about them is bound to be found out as a form of *ignorance*. So then I understand them as: - causation isn't real - this is real - we can study this - and we already are Is that an OK-ish understanding, or have I fallen into a trap? If it is, do all four of these teachings **permanently replace** our deluded conceptualisations?