Agency NOT established by intention

Law, not intention of the parties, may establish agency as in the following cases:

[1] In a partnership, every partner is an agent of the partnership for the purpose of its business (Art. 1818);
[2] In case of certain necessity or emergency, an agency by necessity may arise. An example of this is negotiorum gestio; and
[3] In agency by estoppel, the principal’s actions, silence or inaction leads a third person to conclude that an agency exists.