The notion of “limit” present among the characteristics of modern scientific rationality can be traced back to its emergence and development in the 1600’s within the context of the philosophy of nature. This study shows how such a notion was present and active in those metascientific premises that characterize the foundational moment, the delineation of the method and the development of the figure of modern science. Moreover, the notion of limit, understood as an intrinsic quality of scientific knowledge, was identified and underscored by the philosophy of science in the 1900’s both when it affirmed the irrevocable theoretical nature of observation and when it presented the important question of the demarcation between scientific and metascientific propositions.