# continuous numbering of theorems for the whole article

In the code

\newtheorem{thm}{Theorem}[section]


what should stand in place of section to get continuous numbering (simply Theorem 1, Theorem 2, etc.) for the whole text?

The short answer is "nothing". In LaTeX [...] denotes an optional argument. For \newtheorem when this argument is not present, these environments are number continuously throughout the document:

\documentclass{article}

\newtheorem{thm}{Theorem}

\begin{document}

\begin{thm}
A theorem.
\end{thm}

\section{A section}
\label{sec:section}

\begin{thm}
Another theorem.
\end{thm}

\end{document}


The command \newtheorem has another commonly used optional argument. Writing

\newtheorem{thm}{Theorem}
\newtheorem{cor}[thm]{Corollary}


will use the same counter for Theorems and Corrollaries, so that you get

Theorem 1
Theorem 2
Corollary 3
Theorem 4


Theorem 1