When it comes to our behavior, we have a tendency to rationalize, finding order and justification for our actions. When we maintain a contradictory belief and behavior, often times we naturally change one or the other. We are driven to do so by our cognitive dissonance.
The same is often the case in rational thought alone. We adapt our reasoning to logically follow from certain axioms and assumptions of which need not accurately apply to the world. Believing that there is an inherent openness to all starting points in our reasoning is a deep skepticism. This could lead to a compulsive predilection for denying all claims, asserting that the stronger it is the stronger its unfoundedness must be.
As philosopher Pierre-Daniel Huet wrote, “let any one be convinced that man is an animal so formed by nature, that what appears to him to be true, is false; all you shall propose against this opinion will appear to him to be false or true; if false, he will justly reject it; if true, believing himself to be so made he will still be obliged to reject it as false. Thus it will be easy for him to subvert all reasons that can be objected against his opinion: and we cannot invent one, which will not fall under this general law, that what appears to a man to be of must truth, is most false.”
I do not think this approach would inherently lead to such a regression. I think it is possible for someone to accept assumptions as such and the possibility that one is wrong in whatever subject, be it what you should do in a given situation, politics, or the nature of the universe, and to consider some theories as being still superior to others in their measure of certainty. Yet we must still be skeptical of what it is that is influencing this judgment. Rationality can be preserved at the same time skepticism is maintained; it produces no dissonance.
You have to always acknowledge the assumptions you are making, as a matter of principle, or you are allowing yourself to be blinded. Holding steady to this principle, you will find uncertainty in most everything, and yet much clarity is still be had once the assumptions are accepted. You must have them if you are to have any ideas at all, and to accept them consciously allows for even greater clarity. Clarity is possible in the face of uncertainty. That we should be so certain when we are not even aware of or actively ignoring our assumptions is irrational. To be aware of all assumptions and biases all the time is impossible, but to at the least allow for their existence and search for them is critical if your highest aim is truth.