The key to all science is undoubtedly the question mark.

Doubt is the beginning of thinking and the end of learning.

Problems are midwives, helping new ideas to be born.

Deep in the human soul, there is a deep-rooted need, which is to hope that oneself is a discoverer, researcher, and explorer. In the spiritual world of children, this need is particularly strong.

Those who do not ask will always be with ignorance. ——East Africa.

Those who have no doubts about reading must be taught to have doubts, and those who have doubts must have no doubts. Only by reaching this point can we make progress.

Thinking begins with questions and wonder.

A person who is good at doubting does not doubt what others doubt, but doubts what others do not doubt.

It is more important to ask questions than to solve them.

Questioning customs from all aspects is an inevitable stage of development for every person with a high level of thinking.

You cannot see the truth without doubting.

The ears have no bottom and can be heard from morning till night.