# Different indent only the first line in Section, subsection,

I am writing a document with different indent (spacing) in all section (0.3in), all subsection (0.8in) and all subsubsection (1.4in).

## Only the first line in each paragraphs should be indented but the left margin is not change.

\documentclass[12pt,a4paper,oneside]{book}
\usepackage{geometry}
\usepackage{lipsum}
\geometry{letterpaper}
\usepackage{multirow}

\usepackage{fontspec}

\usepackage{xunicode}

\usepackage{xltxtra}

\defaultfontfeatures{Mapping=tex-text}

\setmainfont{Times Roman}

\usepackage{indentfirst}

\usepackage{titlesec}

\usepackage{titletoc}

\setcounter{secnumdepth}{4}

\titlespacing{\subsection}{1.1in}{1.5ex plus .1ex minus .2ex}{1pc}

\titlespacing{\subsubsection}{1.4in}{1.5ex plus .1ex minus .2ex}{1pc}

\begin{document}

\section{First}

\lipsum[1]

\subsection{Second}

\lipsum[2]

\end{document}


But This is what I need is

One simple solution is change \parindent after \section{}. This can be done automatically redefining \section{}. Example:

\documentclass{article}
\usepackage{indentfirst}

% redefining sections
\let\oldsection\section
\renewcommand{\section}[1]{\oldsection{#1}\setlength{\parindent}{.3in}}

\begin{document}
\section{A section}
I am writing a document with different indent (spacing)
in section (0.3in), subsection (0.8in) and subsubsection (1.4in).
\end{document}


For \subsection and \subsbsection the procedure is exactly the same.

I assumed that you do not need optional arguments in sectioning commands. Otherwise see Renewdefine section with additional argument

Note that paragraphs after a title are not indented by default in English. If you want indent also the firs paragraph, use also the indentfirst package as in the example.