I am going to ask a question that, based on my searches, has been asked repeatedly in the past; unfortunately, the solution that accompanies all of those previous posts does not work. To wit: going to Settings --> Discussion and unchecking the tick box beside "Allow people to post comments on new articles" does nothing whatsoever. The leave a comment/leave a reply box stays firmly planted at the bottom of the page.
I have come across the Disable Comments plug-in that, according to its description, will do this. However, I do not like blackbox solutions and would like to know how comments/replies are in fact turned off. If I have to, I will simply hack the php code and excise the function manually, but it seems rather a shame to have to do something like that.
If my tone offends, I apologize; like so many of the folks who've posted this question in the past, I've spent several hours trying to get this accomplished, to no avail.