Human Motivation in Thomas Reid

According to Reid (1969, 283) motives are an ens
rationis. Because of that they may influence to action, but
they do not act as causes or as agents, that is motives are
only advisory (cf. Seebaß 1993, 329; Lehrer 1989, 210).
Instead motives presuppose an efficient cause, namely an
agent (cf. Rowe 1991, chapter 4), and the agent"s freedom
(Reid 1969, 284). In opposition to Leibniz (1994, 84-85)
who defends subtle reasons Reid (1969) claims that
motives have to be conscious (cf. Seebaß 1993, 269). For
to "be influenced by a motive of which I am not conscious,
is, ..., an arbitrary supposition without any evidence, ... ."
(Reid 1969, 285)