Index: Lib/logging/__init__.py
===================================================================
--- Lib/logging/__init__.py	(revision 73867)
+++ Lib/logging/__init__.py	(working copy)
@@ -631,6 +631,8 @@
         """
         Set the logging level of this handler.
         """
+        if not isinstance(level, int):
+            raise TypeError("level must be an integer")
         self.level = level
 
     def format(self, record):
@@ -1020,6 +1022,8 @@
         """
         Set the logging level of this logger.
         """
+        if not isinstance(level, int):
+            raise TypeError("level must be an integer")
         self.level = level
 
     def debug(self, msg, *args, **kwargs):
@@ -1397,10 +1401,6 @@
         root.addHandler(hdlr)
         level = kwargs.get("level")
         if level is not None:
-            if str(level) == level: # If a string was passed, do more checks
-                if level not in _levelNames:
-                    raise ValueError("Unknown level: %r" % level)
-                level = _levelNames[level]
             root.setLevel(level)
 
 #---------------------------------------------------------------------------
Index: Lib/test/test_logging.py
===================================================================
--- Lib/test/test_logging.py	(revision 73867)
+++ Lib/test/test_logging.py	(working copy)
@@ -263,7 +263,16 @@
             ('INF.BADPARENT', 'INFO', '4'),
         ])
 
+    def test_invalid_log_level(self):
+        # Make sure specifying anything other than an int raises a TypeError.
+        INF = logging.getLogger("INF")
+        self.assertRaises(TypeError, INF.setLevel, "DEBUG")
+        self.assertRaises(TypeError, INF.setLevel, object())
+        self.assertRaises(TypeError, INF.log, object(), 'foo')
+        self.assertRaises(TypeError, self.root_hdlr.setLevel, "DEBUG")
+        self.assertRaises(TypeError, self.root_hdlr.setLevel, object())
 
+
 class BasicFilterTest(BaseTest):
 
     """Test the bundled Filter class."""