Thank you Ernesto,
I like to think of congruency in terms of self-agreement and one might talk about things that hang together well. I've heard of congruency relating to where a person's thoughts, feelings, and actions are in agreement, and I am extending this idea to forms in general. In theories of process; one regards all stable forms as a process that is in agreement with itself.
People are unreasonably put off by non-linear terms. In some cases, that is where the fun stuff is happening. Just as in painting or baking; the order of terms and the directionality of elements within a process become relevant. As soon as you tell some people they need to use a certain ordering instead of applying the commutative and associative rules; they give up.
On uncertainty; the octonions relation to the projective geometry (the geometry of perspective) gives a tantalizing answer to your query. There is a lot to explain with that, however. More is possible than exists in human philosophy... Food for another essay and then some.
More later,
Jonathan