Common sense -- that is to say, comprehension and proficiency in many of the life lessons that are not assigned grades or designations -- does not imply academic sense, nor is the inverse implicate. A successful social figure may be profoundly illogical, while an academic genius may be a villain in any social context. Excluding physical impediments to mental ability, common sense and intelligence are consequences of experience, but it is of course not inexorable that equivalent experience will produce equivalent sense and intelligence. Barring malady, we may say that when considering the average person, the more experience they have in a particular field of study, the greater their depth of knowledge in that field becomes.
With the aforementioned in mind, it is important to recognize that in all cases, every person's ability to make sound judgments must be approached with respectful skepticism and examined critically. This applies, of course, whether or not the realm of discussion being considered lies within a person's experience and education.
A problem often left unexamined by "professionals" is that of hyperdisciplinarity; the condition by which a highly educated person perceives and interprets all experiences through the prism of their specific education, often accompanied by a process in which self-certitude extends beyond the realm of actual understanding and ability. Humans reflexively approach life using those abilities they have most focused on or developed, and thus continue to enhance those abilities to the detriment of others; "The professional ... tends to define his problems on the basis of the technique that he has mastered, and has a natural desire to apply his skills." Here "human nature works against us ... [because] most of us embrace our first answer so strongly that we read less critically than we should. We easily spot data and arguments that confirm our claim, but we just as easily overlook or distort data that qualify or even contradict it. We don't do that deliberately; it's just human nature. You have to guard against this bias, not only in your own work but in your sources, especially when they agree with you." At a somewhat more conscious level, people "quite naturally define as the most important and admired qualities for a citizen those on which they themselves have concentrated." The important point here is that "[t]hose who are expert are so on only a few topics"; and, combining this point with the preceding observations, we observe that as a consequence of the phenomenon in question, people readily display overconfidence when making inferences, and drawing conclusions in domains of knowledge that they have not penetrated at even a surface level.
Over time, by way of hyperdisciplinarity and poor humility, and whether education is narrowly limited or not, one may become increasingly assured of the correctness of all of their decisions and critical standpoints, and begin to believe they have constructed a mental map of reality that approximates the natural world as superlatively as possible. By such a map, certitude creeps beyond the realm of one's experience, extending into fields in which a person's knowledge has not progressed. Furthermore, with a lack of exposure, or through a lack of use, information and ideas may decline even to the point of regression, and it is possible that which had been learned may become unlearned. As age increases, creeping certitude and regressive comprehension complicate the task of even basic education, as arrogance is mistaken for competence, and a person's low self-esteem creates a feedback loop with their stubbornness, thus debasing one's ability for introspection, and effecting an emotional barrier against intellectual growth. New or contrasting ideas, let alone frameworks of thought, are decreasingly permitted through the doors of consideration.
This problem exists most acutely in those that subscribe to a faith-based ethos, regardless of category. Those hoping to approach ideas from a critical perspective must strive to apply reason and skepticism to every belief, thereby improving their ideas by engaging the universe through the iterative process of observation, hypothesis, experiment, and conclusion. In this way, empirical investigation is a process for learning that is apposite to all knowledge and belief.
Because beliefs founded atop faith are beliefs about the world, they are no different in origin or quality than other real world empirical beliefs. Faith-based beliefs therefore occupy the same elemental category as all other empirical beliefs, and do not possess a category peculiar to themselves; and, regardless of context, all manners of empirical belief remain subject to the same truth criteria. Accordingly, the veracity of a faith-based belief must be confirmed using the same truth test that is applied to any other empirical belief: the scientific method. Not that any method will lead us to ultimate or perfect truths -- to expect this would be to expect far too much -- rather, the idea is that we can not know about something if we have not, or can not investigate it.
If you question the idea that faith must be examined with a scientific approach, reflect on your daily conduct. How is it that you have come to approach routine tasks as you do? Why do you believe that you must eat food? Why do you believe the sun will rise tomorrow? Is it for the same reasons that you believe 2 + 2 = 4? Taking a step back, what approach do you take to learning in general? Do you apply a process of observation and experimentation? Or do you eschew the external world and make all decisions based on internal presuppositions (however coherent or incoherent they may be)?
Too-easy-faith runs the risk of working backwards from the desired conclusion, conceiving of supportive explanations that are themselves unsupported, and indeed, unsupportable. Analysis performed using a faith-based framework may thusly lend itself to circulus in demonstrando, which is the diametric opposition of investigation and reasoning. A faith-based framework teaches what to think, where observation teaches how to think. Faith thereby proves itself inane and fantastic precisely because it is difficult to impart the faithful with the tools to move beyond the comfortable, accommodating, and effortless position of self-certifying conviction, and towards observation-based skepticism. Such gains require a mentalist monist version of Bittul Hayesh and the willingness to admit that supernaturalism and objectively free markets, for example, are nothing more than abstract conceptions particular to human consciousness, not physical realities such as a brain cell or bread.
In its quest to prove its own infallibility, faith eliminates one of nature's truly superior achievements that is manifest in humanity: the ability to recognize and address fallacy. Here the perception of Martin Luther was clear: "Whoever wants to be a Christian should tear the eyes out of his reason."
No animal possesses the facility of self-correction to a degree nearly as developed as that of mankind, and reasoning systems that rely on faith or unsubstantiated argumentation purge us of this facility. In this way, faith reduces our ability to discern and dispose of fallacy, thus pushing us down a notch on the evolutionary scale, edging backwards intellectually and regressing us towards the capability of Hylobatidae.
"To the extent that we can put our prejudgments aside, we will increase the usefulness of our observations ... No matter how expertly we observe, we can never have studied all of a situation. In addition, our observations inevitably reflect individual idiosyncrasies. For these reasons, we hold our conclusions tentatively and seek information about what others have observed. Where we find convergence of results we can feel more secure, although still not certain, in our inferences." "Since human beings are prone to err, we are open to the modification of all principles ... the scientific method, though imperfect, is still the most reliable way of understanding the world."