The present volume contains the eleven works of theoretical philosophy composed by Kant during the final fifteen years of the pre-critical period of his thought, which comprises the twenty-three years from 1747 to 1770. During this period Kant composed twenty-five works, of which only one – On Fire (1755) – was not published and of which fourteen were devoted to a variety of themes not covered by this volume: physics and astronomy, geology and meteorology, aesthetics, ethics, and psychology. These fourteen works include the five scientific works of the first five years of the pre-critical period – the two works on physics Living Forces (1747) and On Fire, the two short essays on physical geography of 1754, and the important work of Newtonian cosmology, the Universal Natural History (1755) – and the nine works published during the period covered by this volume but excluded from it for thematic reasons – the three short earthquake essays of 1756; the two short meteorological essays of 1757; the last of Kant's scientific works, the Motion and Rest (1758); an occasional piece of 1760; the essay on morbid psychology, the Maladies of the Mind (1764); and an important work on aesthetics and anthropology, the Observations (1764).

The eleven pre-critical works of theoretical philosophy included in this volume are: (1) New Elucidation (1755), (2) Physical Monadology (1756), (3) Optimism (1759), (4) False Subtlety (1762), (5) The Only Possible Argument (1763), (6) Negative Magnitudes (1763), (7) Inquiry (1764), (8) Announcement (1765), (9) Dreams (1766), (10) Directions in Space (1768), and (11) Inaugural Dissertation (1770). The Physical Monadology has been included because, although it deals with a scientific theme (atomic theory), it also handles important philosophical themes (such as the distinction between physical space and geometrical space); the Maladies of the Mind has been excluded because, although it discusses themes touched on in the Dreams (such as madness, religious mania, and sensory hallucination), it does so from a primarily empirical standpoint.