Package varwidth defines the command \narrowragged that allows us to have narrow paragraphs. It makes all the lines, including the last one, to have approximately the same length:
\documentclass{article}
\usepackage{varwidth}
\begin{document}
Quisque ullamcorper placerat ipsum. Cras nibh. Morbi vel justo vitae lacus
tincidunt ultrices. Lorem ipsum dolor sit amet, consectetuer adipiscing elit. In
hac habitasse platea dictumst.
\narrowragged{
Quisque ullamcorper placerat ipsum. Cras nibh. Morbi vel justo vitae lacus
tincidunt ultrices. Lorem ipsum dolor sit amet, consectetuer adipiscing elit. In
hac habitasse platea dictumst.
}
\end{document}
How can I get the same result, but in addition have every line centered, similarly to the effect of \centering?



\centering. The update to the accepted solution does just that. – Desik Apr 07 '15 at 13:42