The history of the geological sciences has gone through substantive changes in perception, methodology, and changing methods of scientific synthesis. This progression has led to changes in the philosophy of scientific endeavor in the geological sciences. In addition, geological scientists have contributed to the other sciences in changing the methods of demonstrating and validating scientific hypotheses. Scientific approaches useful in one field may not be applicable in all fields of inquiry, and proofs must be demonstrated by differing types of synthesis. Inductive, deductive, teleological, analogous, causal, experimental, developmental, empirical, or conceptual methods have been used in the geological sciences.
Geological thought can be placed in an historical framework from 18th Century Naturalism, to Rationalism of the 19th Century, deductive inferences from causality and experiment, and of special importance, historical syntheses based upon analogous comparison. Actualistic comparisons and quantification were the goals between 1945 and 1965.
The inability to validate geologicl hypotheses in terms of mathematics was a real crisis in geological thought. This inability also was found to exist in physics and mathematics by Heisenberg and Gödel. The introduction of the conceptual model by Rosenblueth and Wiener, 1944-5, provided a new approach to validating hypotheses. Observation could be synthesized by the use of an "idea" or "schema". The model was a useful tool or device that provided the bases for the interrelation of observations, for directed observation, and for prediction of new patterns of observation. Models are now applied to all types of geological observation, and have placed geological thought on a par with other sciences utilizing mathematical theorems. The model approach is a multivariant analysis of independent types of observation. Geologic thought is in transition to new methods and approaches. The new approach is beyond inference, "look alike" comparisons, and statistical statements of association; it is now truly a creative synthesis verifiable by experience, experiment, and new observations.