Human error concerning the geography of the earth has been recurrent throughout historic time. Some kinds of error arise because of the problems of dealing with phenomena in the three-dimensional zone forming earth-space. The broad curvature of the earth, the sheer diversity of earth-space, and the patterns of change through time all form pitfalls for the geographer who is, thereby, liable to error in his descriptive analyses. The problems of placing percepts (things perceived) against concepts (mental abstractions) make for difficulties in analyzing the three-dimensional spatial zone in which geographers work. Among the kinds of error committed there are avoidable varieties, such as the inexact use of descriptive and analytical language, the uncritical use of statistical data, the acceptance of unreliable data, and the confusion of the several kinds of spatial distributions. Less avoidable error derives from the formulation of hypotheses accounting for phenomena which, when critically examined against accurate data, turn out to be inadequate, incomplete, or wrong. Such early hypotheses may actually become stimulants to progress in research; the Huttonian theory of the observable causation for landforms in time produced all of modern landform theory while at the same time producing many errors in analytical explanation. The construct of a model, per conceptualization, risks dangers of obscuring effective explanation owing to the fact that models normally can originally be only caricatures of reality. The Davisian cycle of erosion so obscured progress for a long period by its overacceptance. Social Darwinism, similarly, obstructed effective explanation for a period. The persistence of error becomes an obstruction to progress in geography. The overlong employment of Maury's simple model of the earth's wind systems was such a persistence. Currently the dichotomy of the dualism phrased as physical geography and human geography constitutes an error of persistence. The elimination of avoidable error and the replacement of inadequate to erring hypotheses require a continuing process of critical review, lest avoidable error continue into persistent error. However, on the present errors of inadequate hypotheses may be built the progress of geography in the future. THIS essay offers some thoughts on the origin and persistence of error in geography. Received for publication August 19, 1966. 1 Address given by the Honorary President of the Association of American Geographers at its 62nd Annual Meeting, Toronto, Ontario, Canada, August 31, 1966. Not that geographers have contributed more than their share of error to the unfolding of man's comprehension of the universe. -In all fields of learning, as Joseph Jastrow pointed out, the rare flashes of intuitive judgment illuminate man's slow progress through quagmires of ignorance, thickets of superstition,