Teleology is a form of reasoning which asserts that mysterious forces--be they religious, supernatural, metaphysical, etc.--purposefully steer the course of events toward a particular predetermined outcome. In the 17th-19th centuries, while seeking evidence of "God's perfection in nature" many theologically-minded early scientists -- including Newton, Copernicus, Galileo, Kepler, Cuvier, Darwin, and many others -- often grudgingly uncovered evidence of natural laws that operated independently of divine will. What's more, such natural laws equipped careful observers with the ability to make stunningly reliable predictions about formerly enigmatic natural phenomena. Where once solar eclipses had been perceived as dark and terrifying metaphysical omens, Newton and Kepler demystified such phenomena and drew them under the impassive control of rational science. No longer was there need to fear that which the rational mind could systematically comprehend. Thanks to science, the heavens were no longer the supernatural realm of the gods. Instead, the cosmos became a proving ground to dispel antiquated mythologies and to advance increasingly complex and rigorous scientific cosmologies: from heliocentrism to the accelerating universe and far...Far beyond.
The predictive power of science has made it possible for humans to exert unprecedented control over the natural universe. In the days before science, the winds of human fate were largely blown about at the mercy of the elements. The natural world was a vast, impenetrable mystery that in some cases delivered abundance and prosperity, while in other cases it visited catastrophe: drought, disease, pestilence and destruction. But science changed all that.
Science has provided a key with which to unlock nature's deepest mysteries. For one, geology revealed the mind-blowing extremities of deep time. Christian Church doctrine once insisted that the faithful must believe that the earth was but a few thousand years old. However, geological science has repudiated such beliefs as groundless superstitions. The evidence reveals otherwise. The earth is literally millions of times older than the authors of Genesis ever suspected. Thus, the tale of earth's antiquity is not evidenced in the pages of pre-modern folklore, but it is inscribed in layer upon layer of profoundly ancient rocks. The rocks, the evidence , reveal a much deeper truth.
What's more, scientific understanding of the earth as an integrated geological system has made it possible to make reliable predictions about the future of that system. Although it is not yet possible to predict the precise hour and minute when earthquakes will unleash hell upon the earth, geological science has systematically revealed where and why major geological calamities are most likely to occur. Further, geologists have improved techniques for anticipating geological crises, and that predictive power has enhanced the safety of millions of people who reside in earthquake, volcano and tsunami danger zones.
As as additional example, geological science has also succeeded in developing highly reliable predictive measures of subterranean geological features. This has become an increasingly sought-after divination tool as resource-hungry humans scour the earth to meet the resource and energy needs of a fast-exploding population.
In general, scientific theory progresses on the basis of developing and testing specific knowledge claims about disciplinary subject matter. The more that geologists learn about plate tectonics, the better they become at making accurate predictions about the manner in which the earth's surface will change--and the potential peril that earth dwellers might face from inhabiting earthquake-prone regions of the earth's crust. All this is meant to illustrate that science is capable of making predictions by making hypothetical statements and correlating those knowledge claims to observable facts.
The problem with employing teleology as a means of explaining the course of events is that such a perspective operates on the basis of deductive dogmatism rather than inductive falsifiability. Teleological determinists explain everything that occurs in the universe as an outcome of an infallible master narrative: if an apple falls from a tree, or a star explodes in the Andromeda Galaxy, then determinists will insist that those events transpired precisely how and when they did because an insuperable chain of causality preordained each outcome. The magic of this type of deductive thinking--which, once again, is predicated on a dogmatic allegiance to an "infallible" master narrative--is that it can be used to explain anything and everything. However, as Karl Popper articulated so convincingly, deductive theories that purport to explain everything in fact succeed in explaining nothing scientifically. How much more do we understand about the universe, if we answer questions about its beginning, evolution, and eventual conclusion with the statement: "Whatever happens during the long life of the universe does so because it was meant to be "? Answers of this nature offer no new insights, rather they only succeed in propagating deduction-based ignorance.
Karl Popper and Positive Piffle
Karl Popper went to great lengths to illustrate that all scientific knowledge is provisional. In other words, there is no way to positively prove any statement. Take for example, the relatively straightforward issue of white swans. If one were to try to positively verify the statement, "all swans are white," one would literally need to examine every living swan on the planet. In addition, one would also need to find some way to examine swans throughout the entire expanse of time. No matter how many white swans one might be able to observe in the past and present, there is simply no guarantee that at some point in the future a more colorful swan might arrive on the scene. Since we can never know for sure if, (1) we have succeeded in examining literally every swan from the past and present (i.e., no accurate census information exists for swans), and (2) and there is no guarantee that a red, brown, or black swan might evolve in the future, it is not possible to positively verify the statement that all swans are white. One contrary example will effectively invalidate the entire theory.
Given the difficulties involved in demonstrating the absolute truthfulness of even the simplest knowledge claims, gross overgeneralizations are utterly out of bounds for good scientists. It is simply not feasible for scientists to verify the claim that every phenomena and event--no matter how large or small--in the past, present, and future are all predetermined by an unbreakable chain of causality. To those arch-determinists who confidently claim that the universe is entirely deterministic, Karl Popper would say only this, "Prove it!"