If someone is offering shaving brushes for sale, it is helpful to make an effort to determine the sum of his knowledge of wet shaving. (shaving101.com)
To accept that education is one of the factors, or better, one of the forms of the process which we denote by the very generalised and rather vague term evolution, is therefore to imply that the sum of knowledge and acquirement retained and transmitted by education from one generation to the next constitutes a natural sequence of which the direction may be observed. (religion-online.org)
Indeed, in an opinion issued before the trial, Judge Hart noted, «A patent may have lain for years unheralded, as little a contribution to the sum of knowledge as though it never existed — an idle gesture long since drifted into oblivion. (articles.chicagotribune.com)