Donny

“In the sense of cl. L. discretus, discrete was used by Trevisa (translating from L.), but app. was not in general use till late in 16th c. But in another sense, ‘discerning, prudent’ (derived through French), discret, discrete was well-known in popular use from the 14th c.; this, even in late ME., was occasionally spelt discreet, which spelling was appropriated to it about the time that discrete in the L. sense began to be common; so that thenceforth discrete and discreet were differentiated in spelling as well as in meaning: see DISCREET. Before this, while discrete was the prevalent form for the later discreet, it is only rarely (see 1{beta} below) that discreet appears for the present discrete.] ”

and

“[ME. discret, discrete, a. F. discret, -ète (12th c. in Littré), ‘qui se conduit avec discernement’, ad. L. discretus, in late L. and Rom. sense: cf. It. and Sp. discreto ‘discreet, wise, wary, considerate, circumspect’ (Florio), ‘discreet, wise to perceiue’ (Minsheu). A doublet of DISCRETE, differentiated in sense and spelling.
In cl. Lat., discret-us had only the sense ‘separate, distinct’, as pa. pple. of discernere, whence the corresponding mod.F. sense of discret, and Eng. DISCRETE. The late L. sense, which alone came down in popular use in Romanic, seems to have been deduced from the cognate n. discretion, originally the action of separating, distinguishing, or discerning, and then the faculty of discernment; hence the adjective may have taken the sense ‘possessed of discernment’.
In Eng., discrete was the prevalent spelling in all senses until late in the 16th c., when on the analogy of native or early-adopted words in ee from ME. close e, as feet, sweet, beet), the spelling discreet (occasional from 1400) became established in the popular sense, leaving discrete for the scholastic and technical sense in which the kinship to L. discretus is more obvious: see DISCRETE. Shakespeare (1st Folio) has always discreet.] “