Abstract
We present an introduction to the Eigenvector 1 parameter space, which is an attempt to find a spectroscopic unification for broad-line emitting AGN. It is a 4D parameter space that uses optical, UV and X-ray measures to discriminate between different classes of AGN. Differences in parameter space occupation suggest that radio-loud sources are fundamentally different from the radio-quiet majority. This is a derivative of our suggestion that two distinct populations of broad-line emitting AGN may exist. We suggest that exploration of Eigenvector 1 space at higher redshift and source luminosities would be a valuable program for the proposed new telescopes at San Pedro Mártir.
