“But sir, I don't think I really deserve it, it was mostly bull, really.” This disclaimer from a student whose examination we have awarded a straight “A” is wondrously depressing. Alfred North Whitehead invented its only possible rejoinder: “Yes sir, what you wrote is nonsense, utter nonsense. But ah! Sir! It's the right kind of nonsense!”  

cow (pure): data, however relevant, without relevancies.  

bull (pure): relevancies, however relevant, without data.  

To cow (v. intrans.) or the act of cowing:  

To list data (or perform operations) without awareness of, or comment upon, the contexts, frames of reference, or points of observation which determine the origin, nature, and meaning of the data (or procedures). To write on the assumption that "a fact is a fact." To present evidence of hard work as a substitute for understanding, without any intent to deceive.  

To bull (v. intrans.) or the act of bulling:  

To discourse upon the contexts, frames of reference and points of observation which would determine the origin, nature, and meaning of data if one had any. To present evidence of an understanding of form in the hope that the reader may be deceived into supposing a familiarity with content.  

Here then, good bull appears not as ignorance at all but as an aspect of knowledge. It is both relevant and “true”. In a university setting good bull is therefore of more value than “facts”, which, without a frame of reference, are not even “true” at all.