What does nonjudgmental mean?

An attitude which is free of irrational or unjustifiable moralizing. 

"Nonjudgmental" does not mean all accepting, it means being willing to judge an activity or relationship on the basis of how well it works for the participants and not on some external standard of absolute rightness or wrongness. 

Sometimes it means getting bigger than your judgments, just for a minute, so you can take a good look at them.

Monist Thinking

When we ask a question(or sometimes when we search or sometimes when we date or sometimes when we cook or sometimes when we travel or...), we often assume that there must be only one answer, and thus that if there's more than one answer then our task is not finished and our question not really answered. This is monist thinking.