Science

Science (from scientia, Latin for "knowledge") has come to mean a body of knowledge, or a method of study devoted to developing this body of knowledge, concerning the universe gained through repeated observation and experimentation. See scientific method. Exactly what science and scientific methods are subjects studied by the philosophy of science.

Cerain fundamental assumptions are needed for science. The first assumption is that of realism. Realism asserts that it is possible to understand and explain the Universe using ordinary, empirically accessible, constructs of objective reality. Objective reality is that which is independent of our perception of it. In other words, we must assume that facts are real and not constructed by our perceptions. The essence of realism is the notion that physical objects and events are facts. That is, they exist independently of their being perceived by us.

Clearly, facts may be distorted by our perceptions. A main purpose of science is to eliminate such distortions. The objective reality that science seeks can only be found if our empiricism is pure. That is, we must not use our mind to add things to our observations based on preference, expectation, desirability, preconceptions, biases, limited personal experience, received philosophies, received opinions, etc.

The second assumption of science is that of consistency. Consistency assumes a stable relationship among empirically accessible, objective facts. That is, we believe that facts (or, more generally, phenomena), given identical (or, at least, similar) circumstances of occurrence, exist or behave in the same way at all times and in all places. Another way to say this is that science assumes that there are pervasive laws, scientific laws, on which the Universe is constructed and through which it can be predicted. Of course, consistency depends on reality for its meaningfulness.

The extent to which these two assumptions (consistency and realism) may be attacked, either philosophically or logically, plumb the weakness of science. The frontiers of physics and astronomy do pose challenges to established, perceptual interpretations of the Universe. Ultimately, the objective perfection demanded by the ideal of science may be impossible for humans. Meanwhile, we have bridges to build, ships to navigate, organisms and molecules to classify, diseases to cure, and a Universe full of mysteries to solve. Science has, so far, proved to be the best source of useful information for the solution of the technological problems we face.

Until the Enlightenment, and even after that to some extent, "science" (or its Latin cognate) meant any systematic or exact, recorded knowledge (and the word continues to be used in this sense sometimes). "Science" therefore had the same sort of very broad meaning that "philosophy" had at that time. There was a distinction between, for example, "natural science" and "moral science," which latter included what we now call philosophy, and this mirrored a distinction between "natural philosophy" and "moral philosophy." More recently, "science" has come to be restricted to what used to be called "natural science" or "natural philosophy," and further distinctions have been drawn within it, such as physical science, biological science, and social science. Mathematics is still very often considered a science simply because it is exact and careful; but it is often not thought of as an example of a science because it is not aimed at empirical knowledge.

The term "science" is sometimes pressed into service for new and interdisciplinary fields that make use of scientific methods at least in part, and which in any case aspire to be systematic and careful explorations of their subjects, including computer science, library and information science, and environmental science. Mathematics and computer science reside under "Q" in the Library of Congress classification, along with all else we now call science.

Physical & Biological Sciences

Social sciences

Organization and practice of science: International Council of Science (ICSU)

See History of Science and Technology for an understanding of how these fields came to be. See also scientists for catalogs of people active in each of these fields.

For any science, it is possible to create a catalog of observations of phenomena which are the data of the science, see optical phenomenon. Some phenomena can simply be observed; others are only observable though the use of sophisticated devices or by use of statistics. Experiments are designed in order to make significant observations of phenomena.