Throughout the course of our lives, we are frequently called upon to form opinions regarding matters about which we know very little, or even nothing. For example, to take current issues as examples; is global warming a serious threat to humanity, or is it not? Is capitalism failing, and is socialism a viable alternative economic system? Is it a good time to invest in the rising stock market, or is inflation and a financial crash imminent?
Given that some of the opinions we are required to form are important to our welfare, it is highly desirable that when we form opinions regarding something that we know little about, we do so in a rational way. An incorrect decision, based upon a poorly-formed opinion, can be costly, or even fatal. Our major problem as humans in this regard is the fact that generally we all have genuine knowledge only in respect of the tiny area of existence that we have personally become profoundly familiar with over the course of our lives. A doctor will possess significant medical knowledge, a carpenter significant knowledge regarding wood and its working, and a physicist significant knowledge of the deeper physical world, but nobody can be an authority, or really know what they are talking about, outside what they know to be true from their own personal life-experience.
Of all the relevant knowledge known to the human species at any given time, any individual will only know an infinitely small fraction of it. How, then, are we personally to obtain knowledge concerning the vast area of life that we know little or nothing about, but which may well affect us? The apparent solution to this dilemma is for us to obtain the necessary knowledge from someone else, who is expert in the relevant field.
As long as complex matters of fact are not contentious, and all experts are in general agreement, then we can simply accept the consensual expert agreement as true, and so as our own, with a relatively high degree of being accurately informed. It is on the frequent occasions when matters of fact in which we are not expert are disputed among experts, however, that we have a major problem. This situation gives rise to the Paradox of Ignorance: for how are we to know if the experts whose opinions we choose to accept as being correct are indeed giving us the correct information, and that they are both fully informed and completely unprejudiced? Unfortunately, the personal ignorance of the subject that in the first place requires us to call upon expert knowledge, prevents us from knowing with any certainty if we are actually receiving it, or simply debateable opinion.
Furthermore, while experts in particular fields obviously know far more than the laity about their fields, they are nevertheless sometimes wrong. Consider the scientifically-approved drugs Vioxx and Thalidomide that, after being prescribed worldwide by many doctors, were withdrawn from the market after they were found respectively to be causing death to the elderly and great harm to infants, despite the fact that they had been approved by the FDA. Consider the international computer fiasco of the year 2YK, and also the fact that at one time all the experts believed that the sun revolved around the earth, and so were wrong. The fact that an opinion comes from a reputed expert unfortunately does not guarantee that it is correct, or even correct in most respects.
The two factors mentioned above – the paucity of our individual knowledge and the Paradox of Ignorance – make it effectively impossible for us as individuals to ever acquire the knowledge needed in order to be able to make fully rational and correct decisions in respect of the very many subjects about which we personally know very little. There is, furthermore, a third factor obstructing our acquisition of knowledge, possibly no less confounding than the other two. In adapting psychologically to reality, we each form our world-view through the filter of our individual animal natures, rather than through an objective and unmediated perception of reality itself. We therefore tend to make judgements that accord with and reinforce our existing personal psychological world-views, so reassuring ourselves of their validity. In varying degree, we perceive reality only dimly, through a cloud of our own prejudices. It is not reality as such that we are generally perceiving, but our own personal and very subjective interpretation of it.
Further, although scientists and specialists are taught, as part of their training, to value objectivity above all else, being human, they are generally unlikely to be totally impervious to the various forms of subconscious bias that we all regularly practice.
No matter how intelligent and well informed we might be as individuals, given how very little relatively we each know from personal experience to be true, given the Paradox of Ignorance, and given the human tendency towards prejudice, our individual knowledge and understanding of the world in which we live is clearly very severely limited, and in all probability very, very far from an accurate perception of reality.
As individuals, we may, at best, have during the course of our lives personally acquired the knowledge to be able accurately to ascertain the truth regarding one of the contentious questions listed in the first paragraph. But, even if so, it is highly improbable that we could also accurately answer any of the other four, let alone the multitude of other complex questions invariably facing us individually throughout the course of our lives. As individuals, and no matter how relatively intelligent or well-informed we are, it seems that we actually live in near total ignorance of reality. Yet, astonishingly, when a point of contention arises, we frequently believe that the opinion on it that we happen to hold, accurately reflects reality and is the correct one.