What does objectivity, as being used in this presentation, mean? It means, first, independence from any one individual's perceptions and/or beliefs. It is therefore independent of the subjective experience of any one person. But then upon what IS objectivity BASED? What brings us beyond our own subjective experience and our own subjective model of that subjective experience in such a way as to provide extra value? Let us first review.

First and foremost it is agreement. To the extent that there is not agreement, then, without there being any additional criterion for legitimization of belief, there is nothing to distinguish between one subjective model and another.

The extreme of this criterion of objectivity would be agreement on the part of everyone. To the extent that that agreement has not been achieved, then the model of "reality" falls short of maximally demonstrating objectivity. Note then that complete objectivity is a goal to aim for, not something that can be proclaimed as having been achieved. For instance, everyone might indeed agree currently, but that does not mean that such universal agreement will continue. (Please note that in this presentation, "everyone" should not be taken literally; it generally means "the vast majority of those people in a position reasonably to have an informed opinion.")

And since it is possible, therefore, for everyone to agree and still be wrong, additional criteria of objectivity are desirable.

Those additional criteria have been attained by the development of "rationality," the rules of logic and the rules of evidence, that "everyone" has agreed improves the likelihood of accuracy of the model. And that accuracy means the ability of the model to predict what will happen (in general or in response to doing some particular thing). (Improvement in the ability of the model to predict is the added value provided by "objectivity.")

That is why science (which is specifically committed to the rules of logic and the rules of evidence) is currently the source of the greatest amount of objectivity.

One might ask why we should view science as more objective than general or even current universal agreement, and also why objectivity beyond simply general or even current universal agreement should be valued. There is one specific answer:

Science has demonstrated its capability by enabling us to do that which no other method of legitimating belief has enabled us to do.

Science has enabled us to do that which, before the development of science occurred to any great extent, would have been considered "miracles." And these "miracles" are essentially the ability to predict accurately, i.e., to predict accurately what will happen and especially what will happen if we do certain things. And it is this ability to predict accurately that enables us to do such amazing things.

But even outside of science, there is objectivity that is acquired simply by paying attention to the beliefs of others (as linguistically modeled by them), such that one compares them to one's own. So the effort to achieve objectivity involves at the very least paying attention to the ideas of others, as expressed by them, and attempting to arrive at agreement, by convincing the other(s) or by being convinced by them, or by jointly coming up with an agreed-upon "third alternative." And that process has come to involve, to an increasing extent, the use of the rules of logic and the rules of evidence, or "rationality," recognized increasingly by us as a way of arriving at more accurate beliefs.

It is noteworthy, again, that philosophical postmodernism, the idea that there is no particular value in agreement (my summary statement), represents a move away from objectivity. Postmodernism has helped us to allow each other to express opinions that are different without our getting so upset, even to the point of killing each other, but it does not foster in-depth exploration of difference of opinion in an effort to arrive at agreement. "What is true for me may not be what is true for you, so let's just agree to disagree and move on." The added value of this method of legitimization of belief is, instead of increased ability to predict and therefore to do, increased comfort and joy, and security of group membership.

Now to continue to extend our concept of "objectivity," a fundamental concept that is a part of objectivity as it is being used here is "measurement." Measurement, in turn, is related to predictability.

Measurement results in the ability of two or more individuals to agree, including the scenario in which those two or more individuals may be the same individual but at two or more different times. Thus measurement is a procedure designed to achieve as much as possible agreement among everyone forever. This is why it is a central concept in the more general concept of "objectivity."

First, measurement is a procedure (a repeatable act or series of acts designed for a specific set of situations). It may or may not involve equipment (such as a ruler or a detector). The individual engages in a procedure and observes the result. If this is a measurement, then the individual has some degree of confidence (belief) that anyone (others or self) carrying out the same procedure again will observe the same result. Confirmation of this belief is accomplished by self or other(s) indeed engaging in the same procedure and reporting "yes" or "no" as to whether the same result has been obtained.

Let us take an example. You use a ruler and measure the length of an object, finding it to be, say, 3½ inches long. And let's say you are going to make use of that information to do something important. Now suppose you measured it again and got 2 inches, and again and got 5 inches. Would you be able to complete your project? What is crucial is that the measurement be the same each time. You have to be able to count on it, meaning that the result has to be predictable.

Now if you look really, really closely, each time you measure the object you may come up with a slightly different result. But if the results are only slightly different from each other, you can still do your project. Those differences would be measurement error, that is a recognized phenomenon and poses no problem, because those tiny differences will make no difference, or if they will, then the measuring procedure will be improved so as to make the project possible. Essentially, you will be able to say that the length of the object is 3½ inches or close enough to it not to make an important (significant) difference.

But now suppose you got unpredictably different results, as mentioned above. Would you say that you had successfully measured the object? Successful measurement means measurement the results of which can be relied upon. And that means the results are reproducible. And that means that one can predict the outcome of the measuring procedure, no matter when it is done or who does it. It means that if the measurement is different at two different times, then the length of the object, for instance, can be confidently assumed to have changed, and that others would find the same thing and agree with you.

The ruler is the result of agreement. It is a device that gives predictable results not just for you. Others have used it (or copies of it) and have found that it is reliable, that it produces results that are predictable, independently of who uses it.

If you devise a new method of measuring, how will you and others develop confidence in it? You will use it over and over in a situation in which the results should predictably be the same (or different as predicted), and others will do so also, always seeing if the results of the measurement are what are predicted. The more times that the results are as predicted, the greater confidence is produced in everyone that the measurement procedure is an accurate one.

If your measurement method is sufficiently similar to one that is already agreed to by others, and is described in such a way as to make that clear, then others will probably not need to demonstrate for themselves that the method works, unless perhaps it produces results that seem strange to them.

But the whole idea here is that measurement involves predictability for anyone using the procedure, the prediction being that there will be agreement among people as to the results. And this is why measurement serves to enhance objectivity. It is based upon agreement, if not among people in general then at least between oneself at one time and oneself at another time, and/or among those who most use it. So the most objective measurements involve confident agreement on the part of everyone who is knowledgeable and involved.

And measurement can result in numerical results that are on a scale all the way down to a binary scale of "yes" and "no," and therefore expressible as a "0" or a "1." So when you ask someone whether it is raining outside and he or she looks and tells you "yes," he or she is performing a measurement which you can confirm by going through the same procedure and seeing if you come up with the same answer. You may have the belief that it is not raining outside, but when another person says it is, you will question what was probably a belief in your Subjective Model, and develop a belief that is more accurate because it is more objective, that is, not only based upon agreement with others but also confirmed by measurement, and is therefore part of your Objective Model (as well as, now, your Subjective Model, if you go see the rain for yourself).

So measurement is simply an extension of the concept of the development of objectivity, based upon agreement and upon reproducibility (ability to predict).

Please note that objectivity is not the same as accuracy or correctness.

What we mean by accuracy, or correctness, is that the belief in question leads to predictions, or would lead to predictions, that turn out to be what actually happens, or would happen.

Objectivity is simply a way of increasing the likelihood of accuracy or correctness.

A general way of thinking about these concepts is to regard all "evidence" as consisting of the results of "measurements," and the rules of evidence as having to do with the principles guiding the methods of doing those measurements and the principles guiding the interpretation of the results of such measurements.

The act of "looking to see" can be considered measurement, and the results considered evidence, though the rules of evidence, if usable, would enable one to have much higher confidence in the interpretation of the results of "looking to see." (Most of the time, however, we have to be satisfied with not being able to use the rules of evidence, because there is no way to involve others in the effort, or to involve repetition of observation under varying conditions, at least to the extent accomplished in carefully done experiments.)

The confidence involved in "looking to see" is primarily a phenomenon in the Subjective Model, rather than in the Objective Model. Measurement is carried out as a part of the development of the Subjective Model, as we learn through repetition of experience what to expect, and the results of such measurement are therefore evidence supporting beliefs within the Subjective Model. But it is the addition of the rules of evidence that contributes so much to the effectiveness of measurement and therefore to the recently exponential development of the Objective Model.

So progression toward objectivity is one produced by the symbolic (primarily linguistic) sharing and comparing of beliefs, the use of the rules of logic to identify inconsistencies, and the use of the rules of evidence applied to the results of the use of measurement. And the payoff is increased ability to predict and therefore to do, with consequent reduced risk of making of mistakes.