How can one keep a section{} from being at the end of a page in LaTeX

section{Heading}

Here is some text after the heading.

usepackage{titlesec}
titleformat{chapter}[display]
{normalfonthugebfseries}{chaptertitlename thechapter}{20pt}{Huge}
titleformat{section}
{normalfontLargebfseries}{thesection}{1em}{}
titleformat{subsection}
{normalfontlargebfseries}{thesubsection}{1em}{}
titleformat{subsubsection}
{normalfontnormalsizebfseries}{thesubsubsection}{1em}{}
titleformat{paragraph}[runin]
{normalfontnormalsizebfseries}{theparagraph}{1em}{}
titleformat{subparagraph}[runin]
{normalfontnormalsizebfseries}{thesubparagraph}{1em}{}
titlespacing*{chapter} {0pt}{50pt}{40pt}
titlespacing*{section} {0pt}{3.5ex plus 1ex minus .2ex}{2.3ex plus .2ex}
titlespacing*{subsection} {0pt}{3.25ex plus 1ex minus .2ex}{1.5ex plus .2ex}
titlespacing*{subsubsection}{0pt}{3.25ex plus 1ex minus .2ex}{1.5ex plus .2ex}
titlespacing*{paragraph} {0pt}{3.25ex plus 1ex minus .2ex}{1em}
titlespacing*{subparagraph} {parindent}{3.25ex plus 1ex minus .2ex}{1em}

widowpenalty=1000
clubpenalty=1000

documentclass[oneside,12pt]{article}
defoneline{%
  text text text text abc def ghi text
  text text text text abc def ghi text
  text
}
deffiveline{onelineonelineonelineonelineonelinepar}
deftwentyfiveline{fivelinefivelinefivelinefivelinefiveline}
begin{document}
section{one}
twentyfiveline
%oneline
section{two}
twentyfiveline
end{document}