Sartre makes a devastating use of the "spirit of seriousness" to attack all those human types who accept the ordinary, conventional morality of their own time as if this morality were an eternal, absolute, and necessary truth of the universe. The truth of the matter, Sartre tells us, is that their conventional morality is temporal, relative, and contingent—it is a morality linked to a particular time, it is relative to their own type of society, and it is the contingent outcome rather than the necessary outcome of a variety of social and historical circumstances.

T.Z. Lavine


Chapter 20 defined a core idea as the deepest, most essential meaning of a term in a given language over a specified period of use. Using this understanding, plus root theory maintains that the core meanings of "truth" and "certainty" are not the same. That is to say: in the English language extending far into the past, the deep core meaning of truth and the deep core meaning of certainty are not equivalent. To define truth as certainty or certainty as truth thus does violence to the normal essential meanings of both terms. The plus system aims to capture core ideas in given definitions. (See Definition Essay)

Being able to recognize the distinction between "certainty" and "truth" is fundamental to our ability to articulate affirmative elemental theory and to well rounded use of requirements of sound rational thinking. In commonsense we take into account the distinction between certainty and truth.

Critical philosophy, however, is a different matter. Academic ideologists often confuse the two and soon find themselves immersed in hopeless contradictions.

Truth either is or isn’t, but human certainty comes in degrees. Degrees of certainty are so important to elemental theory that differing degrees have different names. To help clarify varying degrees of certainty plus root theory offers the following definitions and explanations:

Absolute Certainty

Absolute certainty =df knowledge that is fully understood, accurately relates every idea to every other idea, and is infinitely correct in every way. Absolute certainty assumes the knower comprehends each idea in its full extension and in its relationship to every other idea. Absolute certainty precludes doubt of any nature. Absolute certainty holds every thought in total context and continuously relates all knowledge together as one unified whole. Absolute certainty, defined in this full extension of the term, is possible only to an absolute being who enjoys absolute knowledge. It is a basic tenet of plus root theory that: we humans, beset with many limitations, can not attain a state of absolute certainty.

Virtual Certainty

Virtual certainty =df a state of conviction concerning the truth value of a proposition that is so thoroughly established by substantial support that a denial would be absurd. Although humans cannot attain absolute certainty, we can in some matters attain virtual certainty. We can be virtually certain that we exist at a particular moment, that the world exists during its own time, that there are things that exist independent of our knowledge of them, that human understanding is limited, and that, even though limited, we are capable of acquiring much useful knowledge.

Statements abound that we are justified in accepting with virtual certainty. Plus root theory maintains that: because of inherent limitations in our knowledge acquiring apparatus, we humans can never be absolutely certain of the truth of a particular statement but, in many cases, the truth is so patently evident that we are justified in accepting the statement with firm, unwavering conviction. What is more, we would be foolish to reject the truth of the statement that is virtually self evident. This high degree of certainty is virtual certainty.

The term virtual certainty has been around a long time. When justified in accepting a proposition as true with virtual certainty we have all the confidence we need to act with unhesitating conviction. Most people when they say absolute certainty really mean virtual certainty as defined above.

In ordinary speech, it is okay to use absolute to mean virtual. However, in philosophical discussion, it is not okay. In the field of philosophy, a distinction between absolute and virtual certainty is a basic, pivotal, axiomatic necessity if we wish to discuss philosophical ideas in a constructive manner.

Metaphysical Certainty

Metaphysical certainty is the term some philosophers apply to the highest degree of certainty possible for humans to attain. Metaphysical certainty means the same as virtual certainty. It makes no difference in philosophy whether we say virtual certainty or metaphysical certainty as long as we do one or the other.

Resolute Certainty

Resolute certainty is the next degree down from virtual certainty. There are many times in discourse where resolute certainty is more appropriate than virtual certainty. The plus system reserves the term virtually certainty for those propositions that stand before us with ringing clarity — such as I exist at the moment I make this statement. Resolute certainty would apply to statements such as, "Thomas Jefferson died July 4th, 1826." "Water boils at 212 degrees C. at sea level," etc.

Logical Certainty

Logical certainty is resolute to virtual certainty regarding rules of valid logical form. Logical certainty concerns the logical structure of an argument. Logical certainty is a different kind certainty than certainty regarding the truth of an empirical or ontological proposition. We are justified in accepting many logical relationships with resolute or virtual certainty.

Moral Certainty

Moral certainty is firm conviction concerning the ethical justification of actions reached after thoughtful study that has been tested through and against experience. Logically speaking, moral certainty is related to a goal. "If you wish to live a long healthy life, you should avoid smoking cigarettes." In an argument of this type, avoiding cigarettes will not insure a long healthy life, but heavy smoking, if continued long enough, will have a deleterious effect on the smokers health. This presupposes that the person wants to be healthy. If the person’s goal is to be sickly, then smoking is a good way to achieve this goal. Sickly people get more attention than healthy people. Sometimes people desire attention more than they desire good health.

Mathematical & Scientific Certainty

We are justified in accepting many statements and formulas as true with mathematical and scientific certainty. Mathematicians and scientists, on the whole, do well in understanding degrees of certainty. Their subjects develop at an astonishing rate.

When they step out of their fields of expertise, scientists and mathematicians can slide into absolutism or subjectivism but, as long as they stay in their field and stick to their method, they offer astounding examples of sound rational thinking. Scientists appreciate virtual certainty, but know they are not absolute. A genuine scientists continuously works with an open mind.

Sad to say, many sociologists, linguists, psychologists, and others do not qualify as genuine scientists. Chapter 17 gave Max Weber as an example.


Opinion is a judgment about a judgment. (See Q-Gap)

Limits and Possibilities

The above terminology makes clear that human knowledge is possible and valuable but cannot be absolutely certain. Only an infinite being with absolute knowledge can be absolutely certain.

This approach shows that some bits of knowledge are so evidently true that we are justified in accepting them with scientific, mathematical, moral, logical, resolute, to virtual certainty and proceed with confidence. Although we are justified in embracing some knowledge with virtual certainty, we need always to stay humble before the majesty of truth in its full extension and remember we are not absolute beings and we do not possess absolute knowledge.

The principle of Human Intellectual Limitation means that: we humans can’t know anything absolutely (including this statement). The principle of Human Intellectual Possibility holds that: we humans can know bits and dabs of knowledge with varying degrees of conviction from opinion to virtual certainty. The principle of Human Knowledge Value maintains that: although we cannot attain absolute certainty, that which we can know is exceedingly valuable and, if used wisely, can be the means of elevating our lives to ever higher plains of wonder.

Most people know and appreciate these three principles to some degree even though they don’t articulate the thoughts with intellectual precision. Learning to recognizing our limitations and possibilities and the value of knowledge is part of the cultivation of commonsense. As we develop our intuitions, we develop an understanding of these principles. We know it in liminal levels of awareness. We know others know these principles.

There are many other principles concerning knowledge that we, who are educated in civil society, know in the same manner. We understand them in our developed intuitions and liminal awareness. It is cultivated commonsense.

Cultivated commonsense is neither absolute nor subjective. In cultivated commonsense we know in liminal awareness that we are not absolute. We also know that acquiring knowledge and ordering our knowledge in wise priorities is possible and desirable.

These points are basic to understanding plus root theory. They bear repeating.

Only an Absolute Being with absolute knowledge can be absolutely certain. We, humans, are limited beings with limited knowledge and a limited language. The most certain we can ever be is virtual certainty. Because of inherent limitations of sensation, of measurement, of comprehension, of equivocation, of symbolization, and of language in general, virtual certainty is as certain as we can get. Humans are not absolutely perfect beings and cannot attain absolutely certainty. To maintain anything more is a grave root error. It is saying we can do that which a detached examination of our capacity proves with virtual certainty that we can not do.

We can reach virtual certainty. For example, "I am virtually certain that my personal knowledge is limited and that I cannot justify a claim of absolute certainty." There are many statements we humans can confidently accept as true. Some bits of knowledge are so salient and so verified that we can accept them as true with virtual certainty and proceed with unblinking assurance.

Many philosophers who speak of absolute certainty really mean virtual certainty. They say absolute because it is the word available. They don’t want to split hairs or sound pedantic.

But there are times when hairs need to be split and this is one of them. Philosophers should put the business of teaching the limits of human knowledge high on their list. It is a basic plus tenet that: philosophers, when they become philosophers, take on the obligation of promoting both the limits and benefits of the development of human knowledge. It is the duty of philosophers to counteract the primitive tendency of humans to present an idea as if the human speaker was the mouth piece of God. If philosophers say or imply that we can know basic principles with absolute certainty they are untrue to their calling. They place a serious contradiction in the basic premises of the philosophic enterprise. This contradiction can be suppressed into the unconscious but it is still there. It comes out as absolutism or invites over-reaction that results in subjectivism.

As said, many writers in the past, when they said absolute certainty in all likelihood meant virtual certainty or resolute conviction or firm surety as defined in the plus definition set. Most probably, this is what Antoine Arnauld intended when he said "certainty". The same, in most cases, can be said of Cicero, St. Augustine, and others. Many writers with affirmative leanings, if they had been pressed on the matter, would have agreed that they meant something less than absolute certainty in the full extension of the idea absolute.

When we take the idea absolute in its maximum implications, we can be virtually and logically certain that only an absolute being can possess absolute knowledge. At the same time it is foolish to conclude that because we limited humans who cannot claim to be absolute, infinite, unlimited in our understanding, that therefore we know nothing. Both extremes are equally ridiculous. People with cultivated commonsense know this.

Avoiding extremes of absolutism and subjectivism by understanding both the limits and possibilities of human knowledge is important in science. To acknowledge this distinction is particularly important in behavioral sciences that experiment with the relation between human knowledge and human activity. It is especially pertinent in setting up verification requirements. Persons who demand absolute verification before they acknowledge anything unique in human mental life are thinking in totalitarian terms. Demanding unrealistic verification is as unscientific as being naively satisfied with too little. Rejecting all value-judgments because they cannot be verified with absolute certainty is fraudulent reasoning. The major premise is false. Pretending to deduce true conclusions from false premises is unjustified and unscientific.

To say that scientific verification has limits does not excuse sloppy research. It’s the other way around. When we recognize the limits of our knowledge and concede that impartial truth is not of our own making, we become more careful, more concerned with testing facts, and more anxious to be sure that what we say is as accurate as we can make it. The development of affirmative logic leads to good science.

Strange to say, when people slip into attitudes of Thought Conceit (See Chap. 12 & 13), they often become careless in their research and begin to jump to conclusions, as did Max Weber. The attitude of those caught in the grip of thought conceit tends to become the opposite of researchers steeped in Truth Respect [Chap. 13] who have a high regard for accuracy. In discussing Benjamin Franklin, Max Weber’s standards of accuracy were so low that if scientists in general followed his method, science would collapse.

If virtual certainty for us humans serves as well as absolute certainty, then why should we bother to make the distinction. A major reason is to keep philosophy honest. It is important to emphasize the distinction between absolute and virtual certainty in researching elemental thinking. The distinction is a must if we wish to defend the values of civil discourse against assaults from radical cynics. People who aim to support cultivated courteous commonsense and affirmative logic, set themselves up as a target when they claim they know specific propositions with absolute certainly. Their opponent can then shred them into philosophical pieces by demonstrating the absurdity of their claim.

Sound rational thinking emphatically acknowledges a gap between human knowledge and truth in its full extension. Plus root theory is pro-gistic. Pro-gistic means an attitude of mind aiming to progress toward the gist of the matter. If we were already there, we would not be seeking the gist because we would already know every thing and we would have nothing to learn. It is a plus tenet that: the extent of human knowledge is a puddle compared to the ocean of absolute knowledge in its full extension. For a commonsense philosopher to speak as if he or she possessed absolute knowledge denies the very essence of sound rational thinking.

Being able to know various propositions in varying degrees of certainty means that we humans know some truth. We don’t know all truth absolutely but we do know some bits of truth with degrees of assurance that justify incorporating these truths into the body of knowledge we accept with firm surety.

We can feel safe living our lives according to these special truths. If we were to count them, the actual number of propositional truths we are justified in accepting with firm surety in our body of knowledge is huge. From our human point of view, the body of knowledge we have acquired collectively is vast. From an absolute point of view (God’s point of view), our body of knowledge is small.

Even though limited, each of us can speak with confidence about many things. However, to stay realistic, we should keep clear in our mind that our knowledge is not absolute. We are finite beings with finite knowledge. When we pretend to absolute certainty, we slip into the error defined as Thought Conceit (Chapter 12). Thought conceit can go from bad to worse very easily.