Title pretty much says it all.

Discuss.

Does the title statement's certainty stem from introspection, or tautology? Seems like neither to me.

Is anyone going to take a contrary stance to this?

Depends on whether or not walker can explain how any claim that rejects absolute certainty can be taken to be true, without immediately contradicting itself in the process.

And without deductive reasoning, hopefully.

Hey, deductive reasoning is nice, WHERE it works (as it has done roughly 50% of the time XD!!!)

Basically, you cannot be certain that your experience correlates to the outside world, therefore you cannot be absolutley certain of any a posteriori facts. The only thing you can be truly certain of is knowledge gained from reason alone (due to the veil of sense data). However Hume's fork postulates that all a priori reasoning is in fact analytic, and it is up to the rationalist to disprove this. it appears that, due to their failure, Hume's fork still stands, and therefore a priori knowledge is all analytic, I don't think there is any a priori synthetic truth to be found, it just doesn't come up. Therefore all a priori knowledge is in effect tautological.
So the only things we can be certain of are either tautologies, or introspective turths (i am experiencing blue)
at least, thats the way that I see the subject.

Essentially you're saying we could all be plugged into the matrix and there would be no way to disprove it.

in essence, that is what is being implied, yes

I'm not necessarily disagreeing, I just don't understand how claims like these can be made when they're more or less self-defeating paradoxes.

You're also making a claim that cannot, by its own definition, be refuted by any sort of counter evidence, since the claim inherently makes that evidence invalid no matter what. So.. not really a fun debate. Might as well discuss whether or not God exists again.

Actually, you can argue against it with a priori reasoning, you just have to be really really good (like, better than descartes, who failed)

And tbf, it's not a self defeating paradox
now, I'm going to do something that'll make you all hate me:
DEDUCTIVE REASONING!!!!XD!!!!XD!!!XD!!!XD!!!
1) The only knowledge we can have is a priori and a posteriori knowledge (I believe that is an analytic statement, as it is not made true by facts of the world, but by the meanings of the terms involved, and is therefore tautological)

2)A posteriori reasoning is inherently doubtful (again, analytic) the only certain a posteriori knowledge is the introspective

intermediate conclusion 1) the only certain knowledge therefore must be a priori knowledge, or introspective knowledge

3) all a priori knowledge is analytic (THIS is the one premise which can really be argued against, as common sense dictates that premise 1 and 2 are correct. This again, if true, is an analytic statment)

conclusion) certainty is limited to the introspective and tautological

I belive that reasoning in itself is tautological? You guys can correct me if I am wrong.