diff --git a/thesis.tex b/thesis.tex
index 4cb1292..33a14ce 100644
--- a/thesis.tex
+++ b/thesis.tex
@@ -2135,9 +2135,9 @@ the user; the result of querying the environment for the value of
 %
 \dhil{The value of an environment variable may also change during execution.}
 
-An environment variable is an instance of dynamic binding. Dynamic
-binding is a computational effect which dates back to the original
-Lisp~\cite{McCarthy60}.
+An environment variable is an instance of dynamic binding. The idea of
+dynamic binding as a programming notion dates back as far as the
+original implementation of Lisp~\cite{McCarthy60}.
 %
 We will use dynamic binding to implement user-specific environments.