“There's always a lighthouse. There's always a man. There's always a city,”
Ideologues are a crucial part of understanding how and why certain individuals are capable of performing extraordinary acts in certain situations.
Ideologues are an intersection between awareness and physics. They can be described as a sentient incarnation of a certain metaphysical concept. There are ideologues for limitless concepts-- from the primary forces of the universe such as The Eternals Eternity, Death, Oblivion, and Infinity-- to abstractions such as speed or materials like water, or emotions-- or even animals, such as spiders or bats. These include The Seven, also known as the Endless, who derive their harmony from mortal concepts such as dreams, death, and destruction.
Ideologues are and are not sentient. They are, and are not aware. Straddling the boundaries of reality between the Source and the multiverse, they exist in such abstractions that simple binaries such as 'alive' or 'aware' are insufficient. Their purpose requires existence, so they exist to fulfill their purpose. It's a tautology that few can truly comprehend. There are even aspects of ideologues that have sub-aspects to them, being another facet of that core concept.
Ideologues promote their agenda often by empowering avatars or emissaries. Instances of this include Jay Garrick, the first Flash who can draw upon the Speed Force, or someone like Odin who is an ideologue of the concept of Asgard. The Emotional Electromagnetic Spectrum features several such avatars, beings of truly immense power. In the case of the Phoenix Force, it is necessary for the ideologue to occupy a host to focus its power.