Kant's Philosophy of Science: Part II: Opus Postumum

During the nearly twenty years between The Metaphysical Foundations of Natural Science (1786) and his death (1804), Kant was as prolific as ever, writing treatises on practical reason (1788), judgement (1790), religion (1793), peace (1795), morals (1797), and logic (1800). Despite this incredible outpouring of analysis and thought ostensibly unrelated to science, Kant's interest in physics never waned; in fact, he was hard at work on his unfinished magnum opus designed to inform the transition between philosophy--Metaphysical Foundations--and physics. This astounding collection of notes, drafts, and drawings, collectively referred to as the Opus Postumum, remained unpublished for more than a century, deemed un-editable, fragmentary, and, at times, vague--but recent scholarship has unearthed correspondence between Kant and his closest comrades, with whom Kant shared detail about his final major critical work. Paul Guyer, in his introduction to the 1993 translation of the Opus Postumum, quotes Kant from a letter he wrote to his apprentice, Kiesewetter, in the early 1790s: "The transition from The Metaphysical Foundations of Natural Science to physics must not be left out of the system...with that work the task of the critical philosophy will be completed and a gap that now stands open will be filled." Another former pupil, R. B. Jachmann, wrote of this work being "the keystone of his entire system...which was to demonstrate conclusively the tenability and real applicability of his philosophy".

Kant retired from teaching in 1796, and spent his final decade working intensely on this manuscript. Despite his immense dedication for the project, he had occasional doubts in regards to its viability as a text--partially because his strength was waning, and he feared dying before he was able to edit the completed work to his satisfaction. Unfortunately, Kant's executor--clearly lacking understanding about a writer's process--took Kant's vacillation seriously enough to undermine the work, and unenthusiastically presented it to academic colleagues. The dismal result of this mismanagement was the disappearance of the text for fifty years. Guyer details the story of the manuscript's emergence and subsequent publication, including the nearly impossible task of organizing, interpreting, and translating the wealth of pages that comprise the modern version of the Opus. (I've quoted here from the Cambridge edition.)

History aside, the Opus Postumum is an astonishing work, with electrifying insight into physics, indicative of Kant's genius as a logician, but also momentous as an extension, and perhaps clarification and development, of his earlier metaphysical work. He continues his exploration of matter theory; constructs a definition of the concept of relation; discusses the science of nature, and the mechanical formation of the cosmos; discerns the subtleties of time, matter, and mass. Much too much to go into here, but it's well worth a look. After dozens of decades of obscurity, the whole collection of pages can now be purchased at Amazon for a mere $30.

I'll leave you with a fragment of text from an early leaf, what Kant may have considered a summation or notes in a margin, but what I'll call a poem:

Physics itself does not contain

a further transition from merely mechanical

to organic nature founded on the concept of purpose

which transition, and according to which causal laws these

purposes could be explained, exceeds the insights

of human reason

because physics itself here makes a leap, namely to

a nature which can be thought possible only through purposes

for no bridge is placed for us

to reach from one bank

to the other.