Comments Database Listings

You can make database queries any place.

The following returns an array of all approved comments sorted by date:

global $wpdb;
$the_comments = $wpdb->get_results("SELECT * FROM $wpdb->comments WHERE comment_approved = '1' ORDER BY comment_date");

Not to be a total dunce, but how would one add this to a page/post – or enable sorting by author as well?

Sounds like what you need is a comments plugin. There are many out there; I use this one: https://blog.jodies.de/archiv/2004/11/13/recent-comments/

No, I have that comments plugin. I need the ability for users to see & search all comments (and posts) with the ability to sort by date, subject and author.