Accident is a caused happening. (See chance for more.)

Adaption is change within a species.

Anomaly is something which does not fit into an accepted scientific theory or set of theories (a paradigm). Anomalies may be rejected, explained away, ignored, or overlooked. A recognized anomaly is one which is not ignored or overlooked under the current paradigm. It is recognized as anomalous, generally by observation or experiment. A retrorecognized anomaly was not recognized as anomalous under the old paradigm. It is recognized under the new paradigm as having been anomalous under the old paradigm. A reasoned anomaly falls into the gray area between the above two anomalies. Generally, it is not observationally or experimentally anomalous under the current paradigm and is considered to be anomalous by some, but not anomalous by others.

Chance could be categorized according to several different usages. For the purposes of this book, it describes a spontaneous event, or uncaused happening, which indicates the absence of design. By this definition we would not ask what is the chance of a six coming up on one roll of a die, but what is the probability. Similarly, I did not meet a student at the bookstore by chance; rather we met by accident. The reasons/causes were that I went there to check on the amount of books for my class, and she went there to buy a book. I saw a bumper sticker on a car on the Ventura Freeway that summed it up: "Let's not meet by accident."

Chaos Theory holds that many events, which were thought to be random, actually exhibit an underlying, albeit complex, structure. There are systems which do not act in regular or predictable ways which, nevertheless, follow precise laws. These systems may, in fact, involve rather simple equations, but their behavior is very complex.

Equant, in Ptolemaic astronomy, is the point from which uniform circular motion is preserved.

Evolution is the idea that species descended from a common ancestor. (See p. 458 of first edition of On the Origin of Species.) Darwinian evolution is the idea that species descended from a common ancestor with modification through natural selection. (See p. 459 of Origin.)Neo-Darwinism is the idea that species descended from a common ancestor through natural selection of chance mutations.

Facts only refer to specific events. An example of a fact is that yesterday I heated a thermometer and the mercury in it expanded. Facts do not refer to universal claims. An example of a universal assertion is that all metals expand when heated. This claim is not a fact since, for one thing, it is based on the unproven assumption of regularity in nature.

Final cause originally was one of four types of causes described by Aristotle. It is purpose immanent in nature; for instance, the purpose of an acorn is to become an oak tree. Natural philosophers in the Scientific Revolution used this term, but in a Christianized context. For them, purpose or final cause in nature was due to God's intentions.

Guiding idea is a pretheoretical concept in science, such as purpose in nature, which is in itself not testable. When combined with other assumptions, a testable result may occur.

Intention - see purpose.

Normal science is what scientists usually engage in. It is research conducted under an accepted set of scientific theories, and guided by past accomplishments and methodologies. This research increases the precision and extends the scope of knowledge about nature. Anomalies are generated during the course of this research.

Occultation occurs in astronomy when a farther object, such as a star, disappears behind a nearer body, such as the moon.

Paradigm is the received scientific view. It is an accepted set of theories, accomplishments, and methodologies. It is a concept which should be flexibly and loosely, rather than tightly and rigidly, defined and held.

Purpose in nature, as used by natural philosophers during the Scientific Revolution, referred to the design of a supernatural creator, God. Naturally, this design would be the best, most efficient, and all-encompassing one. Thus, events occur in nature due to God's design and not by chance. God's efficient design of the universe encompasses the concepts of simplicity and economy in nature. For the period covered by this book, purpose (including efficiency and economy) is aptly summed up by the oft-repeated phrase, "nature does nothing in vain." Generally purpose refers to intention, aim, or plan.

Science basically consists of 1) collecting and classifying factual information pertaining to nature, and 2) ideas about nature, usually in the form of universal statements, which can be, or have been, tested to some degree. The scientific method involves testing these ideas as rigorously as possible. Non-testable ideas about nature are not scientific and often constitute part of a person's worldview.

Species are populations capable of interbreeding, and producing young that are capable of interbreeding.

[The] Scientific Revolution is generally the period from 1543 (the date of Copernicus' De rev and Vesalius' Fabrica) to 1727 (the death of Newton). During this period, science changed into the form we recognize from our twentieth-century perspective. For more on the dramatic changes which occurred in the Scientific Revolution, see the Appendix.

Teleology is a term not used in this book, but is defined here for completeness. For the period prior to the Scientific Revolution, it can be subdivided into three different classes. The first class is where a purposeful power or principle is considered to be wholly immanent within nature itself. The second is the ascribing of the regular sequences observed in nature to a limited supernatural deity such as Plato's Demiurge. The last class is defined as the intentions of the unlimited Judeo-Christian God in nature.

Uniformitarianism is the belief that all changes which happened in the past, particularly geological ones, can be explained by observable processes existing today. Uniformitarian is the adjective form.

Worldview is an encompassing mental framework and pattern which provides a guide to life. Worldview can be subdivided into two categories. A core worldview is a set of religious beliefs. An articulated worldview is a set of conceptual beliefs.