The first, and lowest, order of thought is an opinion in which one forms a thought based on what one hears, perceives, or imagines.  Opinions have little relation to fact except by improbable coincidence.  An opinion can be completely spurious.  It is based on what we "feel" about a subject.  Once something is a fact, it is usually no longer considered an opinion.  We must get away from allowing opinions to rule us.

The second order of thought is speculation in which incomplete and inadequate information is available.  Significant reaction, if possible, should remain on "hold".  There are situations of exceptional emergency in which one must act before all the pertinent information can be ascertained.  To save the life of a person trapped in a burning automobile one must rush to the car and haul out the victim before one knows how close the fire is to the fuel tank.  Available time in an emergency may limit the order of thought on which we act.  But for the most part, we usually have time to reflect and promote a better understanding of a question.

The third order of thought is knowledge in which one's ideas are based on verified facts.  To establish a verified fact it must be repeatable.  That is to say that any person who would follow a procedure to examine the evidence would find the same conclusion.  Furthermore, it must be reliable.  That is to say that all people considering the same evidence would see the same results, everywhere.  Finally, the fact must be consistent with everything else that we know.  We must establish that we are not experiencing an illusion: what we are studying is valid.  We must be able to use the fact and see it work.  If these three criteria, repeatability, reliability and validity, are established, we may be fairly assured that we are dealing with a fact that is qualified to become a part of our knowledge.

The fourth order of thought is understanding in which one has learned how the facts are inter-related, especially in a constructive form.  With understanding we may manipulate our knowledge with confidence, even though we may be dealing with dangerous material.  Understanding is usually linked with experience.  Experience entails the repeatability, reliability, and consistency of any subject.  The understanding of electricity is a case in point.  One cannot watch men working with high-voltage live wires without appreciating the understanding they have for the subject.  Experience has minimized their fear.

The fifth order of thought is idealistic creativity in which one may draw on one's knowledge and understanding to foresee the best consequences and make innovative construction effective.  In every instance this is the result of hard work and some artistic qualities.  If the result is reliable, used repeatedly, and is deemed to be valid, it becomes knowledge from which others can gain greater understanding.

Opinion polls are big business and their results often influence important policy.  There may be some degree of understanding which is measured in these polls, but this is usually doubtful.  Opinion poll results change quickly and are unreliable.  Even opinions of people of the highest caliber, who are not focused on a subject, are suspect.   The fact that so many elected officials in government positions look to opinion polls to determine how they should behave to keep their job, is the realization of Plato's condemnation of democracy as government diminished to leadership by the masses.

It would benefit everyone to learn the ideas of those who have given measured consideration to a subject and are clear about the nature and organization of their thoughts.