It has long been known, by a simple and general argument, that tidal dissipation within the Earth must slow its rotation, slow the Moon's orbital motion and increase the Moon's mean distance. A hypothesis is made whereby it can be shown, under almost as general conditions, that tidal dissipation must also increase the eccentricity of the Moon's orbit. The exact rate of increase is not determined. However, it is shown that if the Moon were at one time quite close to the Earth the eccentricity would have been at most about 3 × 10−6; i.e., the orbit would have been nearly circular. This agrees nicely with Darwin's idea that the Moon originated near the Earth. At the stage where, according to Darwin, the Earth and Moon each present the same face toward each other and revolve writh a period of 55 present days, the eccentricity will be about 0.2 to 0.4.