Piaget (1968) and Michotte (1963) studied children's perception of physical causality. While emphasizing perception, they deemphasized thinking. The present study extends research by these authors by identifying types of verbal thinking in preschoolers on the basis of judgment of three fundamental physical laws: the first law of static, the law of impulse conservation, and the law of the conservation of energy. Viewing either a computer simulation or realia, 75 children between 4 and 6 years of age who were enrolled in a public kindergarten in Moscow watched a series of physical phenomena which either conformed to or broke a physical law. Subjects described and explained what they saw. Findings suggested that children use three types of verbal thinking when they describe physical laws: play, projective, and scientific thinking. In verbal thinking characterized as play, physical and spatial-temporal relations between objects symbolized and modeled human relations. The projective type of verbal thinking was characterized by: (1) attributing "activity" to one object and "passivity" to others; and (2) the object's activity being determined by its inner state, not by its action. Children's scientific verbal thinking was characterized by equality of physical objects. Results also revealed a developmental shift with age from play to projective interpretation. (Author/RH)