Giving a talk and presenting

The list opens on discorrer, to speak at length on a subject, and its English cousin kept the form while losing the picture inside it. Both go back to Latin discurrere, which is dis- plus currere, to run — not running towards anything, but running about, this way and that, in several directions at once. The noun discursus was that running to and fro, and only in later Latin did it settle on talk, the mind moving from one point to the next. English then took the family twice over. « Discourse » came in as the orderly half: a set speech, a sustained piece of reasoning, and the verb « to discourse on » is what a speaker does from a platform. « Discursive » came in as the disorderly half, and says of a talk or a writer that it wanders off the subject, which is the original running preserved almost intact. So two English words from one Latin verb now name opposite halves of the same hour: the part that holds its line and the part that strays. Once the running is audible, the relatives are everywhere — « excursion », « recourse », « concourse », « cursory ».