Origin and history of conduct

early 15c., conducten, "to guide, accompany and show the way," from Latin conductus, past participle of conducere "to lead or bring together; contribute, serve," from assimilated form of com "with, together" (see con-) + ducere "to lead" (from PIE root *deuk- "to lead").

The sense of "to lead, command, direct, manage" is attested from mid-15c., originally military. The general meaning "to direct, manage, act as leader of" is by 1630s; especially of a musical performance (1791).

The meaning "behave in a certain way" is from 1710. In physics, "to carry, convey, transmit," by 1740. Related: Conducted; conducting. An earlier verb in the same sense was condyten (c. 1400), which goes with conduit.

To conduct is to lead along, hence to attend with personal supervision; it implies the determination of the main features of administration and the securing of thoroughness in those who carry out the commands; it is used of both large things and small, but generally refers to a definite task, coming to an end or issue: as, to conduct a religious service, a funeral, a campaign. [Century Dictionary]

mid-15c., "action of guiding or leading, guide" (in sauf conducte), from Medieval Latin conductus, from past-participle stem of Latin conducere "to lead or bring together," from assimilated form of com "with, together" (see con-) + ducere "to lead" (from PIE root *deuk- "to lead"). The sense of "personal behavior" is attested from 1670s. A doublet of conduit.