I use the article class.
I want a ToC and pages with roman number, so I use the following :
\renewcommand{\thesection}{\Roman{section}}
But the ToC layout is horrible (while page title are great) :

Any help, please?
For the record, I'm using latex since two month and I did great until this problem, which i can't solve by myself. I did a research over the web but I can't find anything about this.

memoirclass you don't have to load thetocloftpackage.) – Torbjørn T. Aug 25 '15 at 07:03