Street level definition of radical skepticism

With the postmodernists of our day radical skepticism has once again made an appearance. This time radical skepticism regarding epistemology. Or, how we know what we know.

Radical skeptics play their parlor game every few centuries, befuddling people who've never encountered such a thing before.

What it comes down to for radical skeptics is not just demanding how can you know 'x', but how can you have *certainty* regarding 'x'.

The answer is we don't need certainty to know things and to operate in this world. We just need probability. Certainty requires omniscience, and that is an attribute only God has. We share some attributes with God, but omniscience, like omnipotence, is not one of them. So we can never know anything with certainty. The way that radical skeptics demand.

We don't need to have certainty though, because probability is enough for us to know things and to operate in this world.