Why drag about this corpse of your memory, lest you contradict somewhat you have stated in this or that public place?

I believe, what emerson meant with that sentence is we should stop dragging around the past and stop bringing it up.

We couldn't control anything in the pass but we still definitely control the outcome of the future. So rather than complaining about what already happen, we should focus on improving ourselves.

This was said by Emerson in Self-Reliance. This can be interpreted in several ways. The simplest is that he is advising against foolish consistency. However, he could also be saying that ALL consistency is foolish and we should stop carrying around the corpse of our habits.