Deep questions drive our thought underneath the surface of things, force us to deal with complexity. Questions of purpose force us to define our task. Questions of information force us to look at our sources of information as well as at the quality of our information.
Questions of interpretation force us to examine how we are organizing or giving meaning to information. Questions of assumption force us to examine what we are taking for granted. Questions of implication force us to follow out where our thinking is going. Questions of point of view force us to examine our point of view and to consider other relevant points of view.
Questions of relevance force us to discriminate what does and what does not bear on a question. Questions of accuracy force us to evaluate and test for truth and correctness. Questions of precision force us to give details and be specific. Questions of consistency force us to examine our thinking for contradictions. Questions of logic force us to consider how we are putting the whole of our thought together, to make sure that it all adds up and makes sense within a reasonable system of some kind.