Unaffectedness
The preceding definition of knowledge is in accordance with the common tacit assumption that the laws of nature, for example, hold timelessly universally. And not only the laws, but also the involved terms or rather the notions or ideas these refer to. A proposition accepted as true may proove false, but the concept of truth as such always remains unaffected. The value of a certain quantity may change, but not the respective number itself, such as the three, or that what it stands for, its meaning, the idea of three.
And so we may realize a constancy we always rely on, the constancy of certain elements of our theories and sciences, mental entities that serve as foundations of all our systems, even those of mathematics and logic. Viewed is this light our definition first of all just features clearly that constancy, giving it a name. We now call it “knowledge” — which is certainly not all-too farfetched.