It helps to understand the explanation of facts in systematic ways. Order comes when theories are constructed or laws are discovered.
Theories and laws are generalisaions. But isolated generalisaions do not constitute a system of knowledge.
The object of science is to present a systematic interconnection of the laws. The laws are interconnected to constitute a system. That means a system is the result of the orderly arrangement of the laws that explain the facts.
A system, as is ordinarily understood, has constituents. The constituents mutually support each other. In a scientific system when some laws are unified under a coherent principle of higher generality that gives insight to understand the laws as well as the system in a more satisfactory manner.
The constituents of a system are mutually compatible with one another and are not a loose bundle. But though the laws belonging to a system are compatible and coherent, they may not be of the same level. Even within a system some of the laws may be having higher generality than the other.
In that case the theoretical order among the laws will be vertical. For in such a system the lower level laws will be deduced from the higher level ones.
In the series of the system the laws at the lowermost level are ascertained by observable evidence whether direct or indirect. If the laws or generalisaions at the lowermost level are supported by the observable evidences then that provides a basis for the indirect justification of the higher level laws and the system itself.
Not only the physical sciences establish systems, the formal studies also have coherent systems. Rather the system in formal sciences like mathematics and logic is more neat and definite as it is purely deductive in nature. For example, in mathematics from a few chosen axioms all propositions in the system are deductively derived by help of some definitions and rules.
There can be different deductive models having each model its own axioms and definitions. Each model is coherent and consistent, for every proposition or theorem is a necessary corollary within the system.
That means the system enjoys consistency and independence for every proposition within the system is logically derivable. Because of this characteristic feature a deductive system is described as pure as the propositions of the system are independent of empirical fact or our experience. But the system that is established in empirical sciences is somewhat different.
Within a system of science the theories which are constructed and the laws which are discovered might be j making a coherent system, but any generalisaions or proposition in the system is not a logical corollary but has its ultimate justification in its objective verification of facts.
That means in a system of science the lowermost generalisaions or laws are ascertained by their j agreement with facts. The veracity of a law in science is founded not on its derivability, j but on being faithful to the facts, Hence even though physical sciences build up systems in a well-formulated manner just like the systems of formal sciences, there is remarkable difference between their systems.
The systems in physical sciences are ultimately fact- based unlike the systems of formal disciplines. Thus a system is coherent within itself, every law within it is consistent with other laws and with the system as a whole; a law even may be deduced from its higher law and ultimately must be in agreement with the empirical facts.
In different branches of science there may be different system of laws. Any branch of science has its own laws. A set of laws in a science establishes a system and there II may be different systems. As science progresses there is more and more systematic presentation of the facts and laws. From a theory other laws are deduced and the laws I ultimately remain faithful to the facts of observation.
This is most conspicuous in developed branches of science like physics. Galileo’s law of acceleration or Kepler’s I law of planetary motion had systematized facts and accorded scientific explanation to 1 them. But Newton’s law of gravitation provided a more comprehensive system and systematized these laws.
That is Newton’s system possessed more explanatory power as its range was wider than the systems prevailing before him. Again Einstein’s theory of relativity still introduced a more comprehensive system as it encompassed a still larger sphere.
It explains Newton’s law of gravitation and much more facts which Newton’s system fails to incorporate within its fold. Thus Einstein’s theory of relativity stands at the apex of the systems in physics for it unifies most of the laws so far discovered. But it is not correct to say that the process of systematization has reached its final stage.
Though the system has made spectacular progress among the empirical sciences as it is getting increasingly widened by explaining new facts even in unanticipated spheres, still the possibility of a higher non-instantial theory cannot be ruled out. For systematization of theories, laws and facts are still open-ended and cannot be said to have been completed.
That is because science gives us progressive knowledge of facts and man’s quest for it will never be final for all times to come.
Thus system building is the very object of scientific inquiry. In its theoretical framework it brings facts under uniformities, uniformities under laws’, laws under higher laws and finally establishes some principles or theories. Hence from the theories of higher order to the facts of observation there are many intermediary stages. The laws at the lowest level are supported by facts of observation.
This process of science makes it a deductive system as the laws are deduced from laws of higher generality. But this deductive system in science is impure because unlike mathematics or logic the system in science goes beyond and seeks its justification in the world of facts.