A horizon is the total set of one's prejudices, but it is also the threshold for all that exists beyond the horizon. In the historical context, because the present horizon reflects the influence of the past, the appropriation of one's horizon is in part identical with the discovery of the other horizon.
The pejorative sense of “prejudice” should apply to people who are unwilling to put their prejudices at stake, who fail to put their horizon at risk in the interaction with another horizon. The approach to another horizon requires bringing in light qualities of one's own horizon. A building is not a work of art if it stands just anywhere, as a blot on the landscape, but only if it represents the solution of an architectural problem.