Under section three (page 139) of Kant's "Introduction," he analyzes different ways that the word "NATURAL" can be understood. His first idea of "natural" meaning "that which properly and reasonably ought to happen" is reflected by the OED's definition of natural meaning "consistent with nature; normal, expected." The idea of "natural" here can be used in the example, "That soccer player was the natural choice" - as in very much assumed or the "reasonable choice."
Kant uses a second idea of natural meaning "that which properly and reasonably ought to happen." This usage of the word can be more easily seen in the example, "That is the natural order of things" - as in, "This is usual, but there can be exceptions."
"NATURAL" Kant "Introduction" Section III, p. 139
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