Since the formulation of the Socratic Method, it has been made reasonably clear that the quest for knowledge is based on firstly knowing that one does not know everything and secondly that the only way to know more about anything is to ask more questions. This does not imply of course that one simply propound any knowledgeable person with a barrage of question. This simply suggests that perhaps not accepting everything at face value without any verification as to its truth or validity is simply not the way to learn.
From the earliest years, the questions, what, who, how, when, where and the all time favorite, why, have been uttered at least a dozen times by any single person. While these are not the keys to critical thinking, they do form an important foundation of critical thinking and that is that it challenges the current knowledge and pushes people to find out more about things and not simple be content with what is present. Herein lays the first benefit of critical thinking.
It challenges the mind to ask more questions and remains at the very center of the quest for knowledge. Without critical thinking, everything in itself would become the rule and nothing would ever be the exception. A falling apple would be a different rule in itself and not connected to a flying bird when in it is in fact clear that through the exercise of critical thinking gravity and all the other forces are at work on these two objects. Secondly, critical thinking pushes at boundaries. To simply say that a truth is truth in itself is naive.
Critical thinking plays an important role in all of this because it does not alter the truth but simply brings more of it into light. It reveals and enlightens and only constricts those who are too bound and caught up in the piece of truth that they have come to know. Critical thinking provides other clear benefits but none as important as its role in uncovering the complete truth and driving the quest for knowledge for the benefit of all mankind. After all, critical thinking in itself would never even be the subject of this discussion if it never existed.