OBSERVATION, OBSERVANCE.--_Observation_ contains the idea of "looking at";
_observance_, of "keeping," "celebrating." "We speak of the _observation_
of a fact, of a star; of the _observance_ of a festival, of a rule."[29]

PROPOSAL, PROPOSITION.--"A _proposal_ is something proposed to be
done, which may be accepted or rejected. A _proposition_ is something
proposed for discussion, with a view to determining the truth
or wisdom of it."[30]

RELATIONSHIP, RELATION.--_Relationship_ properly means "the state of
being related by kindred or alliance": as, "A relationship existed
between the two families." _Relation_ is a word of much broader
meaning. It does not necessarily imply kinship.

SOLICITUDE, SOLICITATION.--_Solicitude_ is "anxiety"; _solicitation_ is
"the act of soliciting or earnestly asking."

STIMULATION, STIMULUS, STIMULANT.--_Stimulation_ is "the act of stimulating
or inciting to action"; _stimulus_, originally "a goad," now denotes
that which stimulates, the means by which one is incited to
action; _stimulant_ has a medical sense, being used of that which
stimulates the body or any of its organs. We speak of ambition as
a _stimulus_, of alcohol as a _stimulant_.

[25] "Foundations," pp. 53-56.
[26] A.S. Hill: Principles of Rhetoric, revised edition, p. 18.
[27] The Century Dictionary.
[28] A.S. Hill: Principles of Rhetoric, revised edition, p. 39.
[29] A.S. Hill: Principles of Rhetoric, revised edition, p. 39.
[30] The Century Dictionary.