Dealing with factors affecting economic growth in knowledge-based societies, the author shows that the interaction between material and nonmaterial values is the ultimate source of all economic growth. The model thus developed predicts the quantitative facts concerning business cycles better than the conventional real-cycle models, while also producing a new growth path whose existence is verified by empirical facts. The results provide strong evidence of the economic relevance of nonmaterial values, and also prompt a new view of the shastic elements in the business cycles.