[pmoriarty]

Even if there is some sort of "shared context" (more commonly known as "objective reality") your view or understanding of it could still be deceived, hallucinating, simply mistaken, insane, etc. These are not solipsism. What they are are possible obstacles to your connection to any shared context or objective reality.

[redial]

Sure, but they don't change the fact those are the only 2 options.

And in the "shared reality" option, consciousness is somewhat measurable.