According to Reinhart Koselleck, in every moment a congeries of “temporal strata” are effectively co-present, but not necessarily coherent, hence the “simultaneity of the nonsimultaneous.” Contrast this with the notion of a zeitgeist in which every aspect of a historical moment is integrated by some master principle. There are so many trajectories active in any present that it is unlikely that one might coordinate all of them, if not unwise even to believe that they are coordinated. Not only does each historical present demonstrate at best rhizomic or patchy coherences across domains, but it also registers different paces and intensities in the temporal deployment of the domains. Nevertheless, coherence remains a compelling regulative ideal. Fortunately, path-dependency—cumulation as constraint—is a discriminable feature of the several distinct “layers of time” or diachronic flows co-present in any given historical moment. Moreover, that some strata of experience remain roughly constant enables us to appraise the variation of others. If too many elements enter into simultaneous crisis, if we hit the “perfect storm,” then our capacity to comprehend (like that of our objects of inquiry) may be severely impaired. These insights from Koselleck are eminently applicable and deserve recognition and gratitude in historical epistemology.