\documentclass{article}
\usepackage{epigraph}
\begin{document}
\section{One}
\epigraph{My soul, seek not the life of immortals; but enjoy to the full the resources
that are within your reach}{\textsl{Pythian Odes}\\\textsl{Pindar}}

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

\section{Two}
\def\epigraphflush{center}
\epigraph{The whole is more than the sum of the parts.}{\textsl{Metaphysica}\\\textsl{Aristotle}}
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

\section{Three}
\def\epigraphflush{flushleft}
\def\textflush{flushright}
\def\sourceflush{flushleft}

\epigraph{Example is the school of mankind, and they will learn at no other.
}{\textsl{Letters on a Regicide Peace}\\\textsc{Edmund Burke}}
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.


\section{Four}
\def\epigraphflush{flushright}
\def\textflush{flushleft}
\def\sourceflush{flushright}
\begin{epigraphs}
\qitem{My soul, seek not the life of immortals; but enjoy to the full the resources
that are within your reach}{\textsl{Pythian Odes}\\\textsl{Pindar}}
\qitem{The whole is more than the sum of the parts.}{\textsl{Metaphysica}\\\textsl{Aristotle}}
\qitem{Example is the school of mankind, and they will learn at no other.
}{\textsl{Letters on a Regicide Peace}\\\textsc{Edmund Burke}}

\end{epigraphs}

\end{document}