What is today supported by precedents will hereafter become a precedent.

The line warns that appeals to precedent are never neutral: when an action is justified by earlier examples, it simultaneously adds another example to the record and can normalize what was once exceptional. In Tacitean terms, this is a mechanism by which power expands—especially under autocracy—because each “one-off” measure, once accepted, becomes part of the tradition future rulers can cite. The quote thus captures a self-reinforcing dynamic in law and politics: precedent both constrains and enables, and the present quietly legislates for the future by what it tolerates today.