Knowledge and intelligence do not make an unbiased thinker; it is the ability to eliminate emotion to enable oneself to evaluate: fact from fallacy, deduction from delusion, the significant from the superfluous, and the material from the myth
Reasoning is the mental process humans use to make sense of the world; and to understand what is true and what is false. The conventional approach to analyse ideas is to say there are just three ways to reason: deductive, inductive, and abductive reasoning. In non-technical language, deductive reasoning relies upon logic (as the full scientific method), inductive reasoning trusts credible inferences (as the police method), and abductive reasoning judges the best explanation from various points of view (as the courtroom method). In the opinion of Wikipedia conclusions of a deductive argument are certain, while the truth of the conclusions of inductive and abductive arguments are only probable, as they include assumptions in relation to the truth and completeness of the evidence used. This is easily refutable as virtually all deductive reasoning, including the complex sciences, involves assumptions. What the academic approach also fails to consider is there are other mental processes going on at the same time as "reasoning". What is noticeable is that these parallel human mental factors dominate our entire thinking activity and make the conventional way of looking at human reason irrelevant.
An example: we will examine the way people make their judgements. Imagine two ideas or people with a 50% popularity rating with the public. The thinking of almost everyone goes like this: I am sensible, logical and sufficiently informed and kind, so my evaluation will be correct - with the educated likely being even stronger in this belief. They then learn that the percentage support for each idea or person can be split 90 - 10 with one so-called group of people and 10 - 90 with another "group"; because people can have different ways of reaching their decisions. Both groups then use their reason to believe their group is right due to their superior experiences, education, higher moral behaviour, or intelligence; and those who disagree are likely to be less informed, less moral, or even mentally challenged.
However, a moments thought shows that this thinking process has a fatal flaw because in the real world no matter how open-minded and objective you believe your opinion to be, for many topics, there will almost certainly be another equally (or more) objective and honest person who will believe the exact opposite. We need to understand these issues as they can result in inconsistent thinking and occasionally dysfunctional behaviour.
How humans actually behave during their reasoning processes involve two connected but typically unconscious factors. They are the degree of reliance people place on their understanding of what is real about the world (Reality = the nature of the material and spiritual worlds, if any) and the degree of reliance they place on what is actually true in the world (Truth = factual truth as compared to individual truth). These aspects include our motivating attitudes and philosophies and provide direction to our "belief system", which operates like a template in our minds to shape the direction of our thoughts. A good example is that humans can, and frequently do, bias the truth and refuse to accept it when it is counter to what they want to be true (egoistic biases).
This template in our minds needs to be managed otherwise we will be controlled by our many complex biases. This can only be done on a moment by moment basis by reflecting upon our assumptions and our motivations. Few people are capable of this; but it is essential because what we rely upon for our reasoning process regarding Reality and Truth is frequently not what we say and think we believe. This means while we really do have particular foundational beliefs we can also mislead ourselves to rely upon ideas that are significantly counter productive to our principles (one extreme example being the Stockholm Syndrome). This problem is best approached by managing our template by understanding our underlying goals and assumptions - which can be called our personal paradigm.
For all matters, including science, religion, and politics it is far more effective and practical to evaluate the theoretical topic of paradigms and not, as we frequently do, to be judgemental about people. One matter is evident: those who form their opinions based on how to win the private or public debate for ideas will have far different paradigms to those who only wish to find an interesting and productive career and to have the freedom to think and believe for themselves.