[1] Metzger's most widely acclaimed work is Psychologie: Die Entwicklung ihrer Grundannahmen seit der Einführung des Experiments[2] (Psychology: The development of basic principles since the introduction of the experimental method).
[3] The early major work Gesetze des Sehens (Laws of Seeing) first appeared in serial part issues, edited by the Senckenbergische Naturforschende Gesellschaft in Frankfurt.
In this work Metzger supplemented his collection of phenomena from everyday perception and the fine arts, always endeavoring to find ever more compelling illustrations for the Gestalt point of view.
As Heinz Heckhausen has pointed out this work is a masterpiece for those who come to it without an intense background in the psychology of perception; in a nontechnical style Metzger moves the reader toward a deeper experience, and sometimes an altered conception, of the visual world.
His guiding principles in these applied endeavors were developed in his last two books, Schöpferische Freiheit (Productive freedom, 1949, 1962) and Psychologie in der Erziehung (Psychology in education, 1971).