This article, which makes no claim to scholastic profundity, arose from a discussion as to whether the use of a supine to translate a purpose clause after misit was admissible in G.C.E. ‘A’ level Latin Prose.
This construction, which describes action as a goal of motion, is explained in probably all syntax books used in schools: e.g. North and Hillard, Latin Prose Composition, has a note (p. 110) in which the following examples are given of ways to express purpose:
Legates misit ut pacem peterent
qui pacem peterent
ad pacem petendam
pacis petendae causā
pacem petitum
It is also noted that the future participle (pacem petituros) occasionally occurs in this sense. This use is so rare that I do not propose to consider it.