diff --git a/src/error/ErrorManager.java b/src/error/ErrorManager.java
index bd065a1..2a20dc6 100644
--- a/src/error/ErrorManager.java
+++ b/src/error/ErrorManager.java
@@ -3,7 +3,7 @@ package error;
 import java.text.MessageFormat;
 
 /**
- * Prints error messages.
+ * Prints error messages and potentially terminates the application.
  */
 public class ErrorManager {
 
@@ -15,27 +15,13 @@ public class ErrorManager {
     public static final String ANSI_PURPLE = "\u001B[35m";
 
     public static void generateError(LispException lispException) {
-        generateError(lispException.getMessage(), lispException.getSeverity());
-    }
-
-    /**
-     * Prints out the specified error message to the console and decides whether
-     * or not to terminate the currently running program.
-     *
-     * @param message
-     *            the error message
-     * @param level
-     *            the "criticality" level of the error
-     * @postcondition If <code>level &gt;= CRITICAL_LEVEL</code> the currently
-     *                running program has been terminated.
-     */
-    public static void generateError(String message, int level) {
-        String color = (level >= CRITICAL_LEVEL) ? ANSI_PURPLE : ANSI_RED;
-        String formattedMessage = MessageFormat.format("{0}error: {1}{2}", color, message, ANSI_RESET);
+        String color = (lispException.getSeverity() >= CRITICAL_LEVEL) ? ANSI_PURPLE : ANSI_RED;
+        String formattedMessage = MessageFormat.format("{0}error: {1}{2}", color, lispException.getMessage(),
+                                                       ANSI_RESET);
 
         System.out.println(formattedMessage);
 
-        if (level >= CRITICAL_LEVEL) {
+        if (lispException.getSeverity() >= CRITICAL_LEVEL) {
             System.exit(1);
         }
     }
diff --git a/src/main/LispInterpreter.java b/src/main/LispInterpreter.java
index 08dafe5..3236019 100644
--- a/src/main/LispInterpreter.java
+++ b/src/main/LispInterpreter.java
@@ -32,14 +32,14 @@ public class LispInterpreter {
 
     /**
      * Evaluate the S-expressions found in the file given as a command-line
-     * argument and print the results to the console. If no file name was
-     * given, retrieve the S-expressions from standard input.
+     * argument and print the results to the console. If no file name was given,
+     * retrieve the S-expressions from standard input.
      *
      * @param args
-     *  the command-line arguments:
-     *  <ul>
-     *      <li><code>args[0]</code> - file name (optional)</li>
-     *  </ul>
+     *            the command-line arguments:
+     *            <ul>
+     *            <li><code>args[0]</code> - file name (optional)</li>
+     *            </ul>
      */
     public static void main(String[] args) {
         LispParser parser = null;
@@ -51,7 +51,20 @@ public class LispInterpreter {
             try {
                 parser = new LispParser(new FileInputStream(args[0]), args[0]);
             } catch (FileNotFoundException e) {
-                ErrorManager.generateError(e.getMessage(), ErrorManager.CRITICAL_LEVEL);
+                ErrorManager.generateError(new LispException() {
+
+                    private static final long serialVersionUID = 1L;
+
+                    @Override
+                    public int getSeverity() {
+                        return ErrorManager.CRITICAL_LEVEL;
+                    }
+
+                    @Override
+                    public String getMessage() {
+                        return e.getMessage();
+                    }
+                });
             }
         } else {
             // no file name was given, create a 'LispParser' on standard input
@@ -63,7 +76,7 @@ public class LispInterpreter {
             System.out.print(PROMPT);
         }
 
-        while (! parser.isEof()) {
+        while (!parser.isEof()) {
             try {
                 SExpression sexpr = parser.getNextSExpression();
                 String result = MessageFormat.format("{0}{1}{2}", ANSI_GREEN, EVAL.eval(sexpr), ANSI_RESET);
@@ -75,14 +88,27 @@ public class LispInterpreter {
                 ErrorManager.generateError(e);
             } catch (RuntimeException e) {
                 LispInterpreter.erasePrompt(interactive);
-                ErrorManager.generateError(e.getMessage(), 0);
+                ErrorManager.generateError(new LispException() {
+
+                    private static final long serialVersionUID = 1L;
+
+                    @Override
+                    public int getSeverity() {
+                        return 0; 
+                    }
+
+                    @Override
+                    public String getMessage() {
+                        return e.getMessage();
+                    }
+                });
             }
 
             if (interactive) {
                 System.out.print(PROMPT);
             }
         }
-        
+
         System.out.println();
     }