The testing movement has had the effect of stressing “nature” rather than “nurture” as the great determinant of conduct--over-stressing it, indeed. But the creative type of school-experience yields data that help towards a balanced understanding of the factors. In general, this experience tends to make both nature and nurture stand out; the old bipolarity of heredity-environment, nature-nurture, remains, but both poles are illuminated. This type of school makes obvious the differences in native gifts, but it shows likewise that conditions created by adults have prevented us from knowing what gifts are there. Whenever a given sort of conduct is oft-repeated, our first, incautious impulse is to guess that the conduct in question is produced by some specific quality or bent of one’s original nature. The absence, or even the great infrequency of anything, is taken, similarly, as evidence that there is a vacant place in one’s nature. Thus a bad mental habit, a fallacious mode of judging, gets control of us. “It’s his nature,” we say, not stopping to consider whether the whole of his capacity or only a fraction of it has been displayed. What the experimental schools are doing is to bring into action capacities that commonly are under-exercised and therefore not recognized as existing. These schools are proving that there is more in human nature than we had dreamed of in our philosophy. The method of the proof is, in principle, simple: Make conditions favorable for the maximum voluntary exercise of any and all worth-while capacities that may possibly be there. When this is done, behold, pupils “take an interest in” many things that have been regarded as beyond their range. We are finding out that teaching of the traditional sorts has habitually aimed under the heads rather than over the heads of pupils. An intellectual springiness that teachers and parents failed to discover or produce by the methods of prescription, spontaneously appears under the new conditions. Conduct now occurs that is better by far than old-type schools ever thought of requiring or even recommending.