Your premise seems to refute, or invalidate, itself – to wit: if "certainty does not exist", then it is also uncertain that "certainty does not exist".

If we cannot be certain of anything ourselves, does that mean that certainty does not exist? — Kranky

Isn't this a performative contradiction? How can you be certain of something while claiming you can't be certain of it?

What I mean is: If I cannot be certain that I exist, can it still be said that it is certain?

There is a belief that I exist, but it might not be me thinking it. The thought of my existence could exist without me.

I think my question is:
So, if there is no certainty of my existence, can it be said that the belief of my existence is certain? — Kranky

If we cannot be certain we exist then perhaps we have bigger concerns than philosophy.

Your question isn't clear to me. Who is not certain that you don't exist - the rest of us, or yourself? How you feel about yourself has very little impact upon whether others think you exist. But naturally I don't know if you exist. For all I know you may be a fat, Russian apparatchik typing away inside some dreadful concrete brutalism in Novosibirsk.

Hi Kranky. First, what is 'certainty'? Is it being free from doubt? Because I can doubt is just a state of mind in which you are suspicious that something isn't true, not that it actually isn't true. What you're likely looking for is 'know'. Can we know things? Yes.

First, take the fact that you experience. By experience I mean the flood of every sensation and awareness that you are in one big blob. If you can't experience, then you can't doubt that you experience can you? So you know that there is experience.

Further, you are able to part and parcel that experience into 'experiences'. "That" is a field of grass. "That' is a blade of grass. "That" is a piece of a blade of grass. How do you know you can do this? Well, if you don't exist, you can't say, "I don't exist". If you can't parcel experience into 'experiences' or discrete identities, you can't form the words, "I can't know anything." Your ability to speak and think and yes, even doubt, confirm that these are things you know.

For knowledge is simply a deduction of one's experiences that do not contradict reality. Is there much you can know beyond that? Yes. If you're interested in more, feel free to read here. https://thephilosophyforum.com/discussion/14044/knowledge-and-induction-within-your-self-context There is a summary a few posts down if it helps.