"The dilemma... of modern man is that the quest for objectivity in the sensible world, now so materialistic in its outlook, is at the same time so deeply undermined by the relativism of modern thought. Empiricism and scepticism share the same bed in our culture, producing the offspring of materialism, totalitarianism, and collectivism. Essentially, this is so because if the truth resides in the object itself, then man, too, is merely an individual part of nature. If, on the other hand, the truth lies in the subject, then truth becomes relativised to the vanishing point. Thus, the gulf between 'the two cultures', as C. P. Snow called them, the objectivism of science and the subjectivism of art, ultimately will polarize society.... This then is the fundamental misconception of our times, that we have located and fixed truth within the object-subject relationship. It inhibits any capacity to believe in truth outside of space and time. So, the external reference, to truth in God, has vanished in much of our culture.... It is only when we know God as the Creator that we recognize that all truth is God's truth, and that He has created both the objective world and the mind of man to think His thoughts after Him."
James Houston,I Believe in the Creator, Eerdmans (1980).
The debate over the status of knowledge, particularly scientific knowledge, has been a major theme of philosophy in the 20th century. The skepticism of Hume led to the Enlightenment emphasis on scientific observation (empiricism) as the only source of true knowledge, as opposed to the acceptance of "metaphysical" notions such as the existence of God, soul, mind, etc. Positivism, as a simplistic view of intellectual progress first proposed by Comte in the early 19th century, gained dominance in the first half of the 20th century, culminating in the "verification principle", which stated that no proposition could be considered true, or even meaningful, unless it could at least in principle be verified by observation.
The trouble was, the verification principle itself could not be verified by direct observation. It was in fact a "metaphysical" proposition. Since there appeared to be no escape from this situation, positivism eventually collapsed around the middle of the 20th century.
The pendulum swung almost immediately to the opposite extreme, with the publishing of Thomas Kuhn's Structure of Scientific Revolutions in 1962. He characterized science as dominated by a sequence of distinct paradigms that were not readily translatable from one to the next, so that one could not even assume that science was cumulative across the paradigms. He was unable to fully deny the charge of relativism: that in effect science was no more objective an endeavor than fashion design.
The acceptance of Kuhn, especially among social scientists, has been enthusiastic and unquestioned. Constantly new "paradigms" are being proposed. In the 1960's the general intellectual culture has changed radically -- from an emphasis on the unity of science and rejection of "unscientific" ideas, to a relativistic drift and inability to control the onslaught of new theories, with no clear way to demarcate science from non-science. (Even some Christian groups justify their claims based on Kuhn's philosophy, e.g. when they say that 'both creationism and science are religious'.) That is the situation as we see it today.
Del Ratzsch, a philosopher at Calvin College, summarizes the situation as follows:
"But though there has been a movement away from many of Kuhn's views about science, a simple return to some earlier position would not do; the difficulties of those positions are well known. Kuhn has, in that respect, provided a needed corrective to the rigidity, formality and autonomy of earlier conceptions, and those lessons are not to be forgotten.
"The precise direction to take is not exactly clear, but it has become increasingly apparent where the direction should be sought. In some sense, the positivists and the later followers of Kuhn and other radicals were at opposite ends of one scale. Both seemed to think that rationality, objectivity and empiricality were all-or-nothing propositions. The positivists opted for the "all" end with all three. As much as possible, everything had to conform to a rigid logic, subjective factors had to be isolated and detoxified, and everything had to rest on the empirical (empiricism). At the other end, the major episodes in science (revolutions) were nonrational. Subjectivity entered even into perception. And the empirical sometimes couldn't so much as be seen; if it was, it could often be safely ignored. Both extreme sides accepted the all-or-nothing assmption, disagreeing only on which end to jump to.
"But it is not at all clear that the choice is between 'nothing goes' or 'anything goes'. Contemporary philosophy of science has been searching for some middle ground where reason, observation and objectivity have an appropriate place, but where the human factor is at least that -- a factor.
Del Ratzsch, Philosophy of Science: The Natural Sciences in Christian Perspective Inter-Varsity Press (1986).
"To study history means submitting to chaos and nevertheless retaining faith in order and meaning."
Hermann Hesse
This dilogic attempts to moderate the epistemological problem by avoiding the extremes of both positivism/certainty and relativism/chaos. It uses the language of Michael Polanyi (Personal Knowledge, 1958) to emphasize the fact that knowledge is a possession only of persons, and all propositions entail a personal faith commitment. Yet there is a common commitment among scientists -- particularly physical scientists -- that they are searching for a description of the unique, coherent, objectively real world. Their success in such endeavors as geophysics, cosmology, particle physics, molecular biology, medicine and computer science serve to demonstrate the validity of this endeavor, although from the point of view of positivism it is based on nothing more than an assumption, or a "justified belief".
The quest for absolute certainty has thus become a philosopher's empty debate, while practical scientific knowledge -- that is, the personal knowledge of scientists -- continues to accumulate in a fairly coherent system, from the Standard Model of particle physics to relativistic cosmology. In fact, I may now confidently say that it is largely the success of scientific practice that has served to refute the two extreme philosophies of positivism and relativism.