diff --git a/activemodel/lib/active_model/validations/exclusion.rb b/activemodel/lib/active_model/validations/exclusion.rb
index 209b1c76f9..f8759f253b 100644
--- a/activemodel/lib/active_model/validations/exclusion.rb
+++ b/activemodel/lib/active_model/validations/exclusion.rb
@@ -1,6 +1,11 @@
 module ActiveModel
   module Validations
     class ExclusionValidator < EachValidator
+      def check_validity!
+        raise ArgumentError, "An object with the method include? is required must be supplied as the " <<
+                             ":in option of the configuration hash" unless options[:in].respond_to?(:include?)
+      end
+
       def validate_each(record, attribute, value)
         return unless options[:in].include?(value)
         record.errors.add(attribute, :exclusion, :default => options[:message], :value => value)
@@ -30,10 +35,6 @@ module ActiveModel
       def validates_exclusion_of(*attr_names)
         options = attr_names.extract_options!
         options[:in] ||= options.delete(:within)
-
-        raise ArgumentError, "An object with the method include? is required must be supplied as the " <<
-                             ":in option of the configuration hash" unless options[:in].respond_to?(:include?)
-
         validates_with ExclusionValidator, options.merge(:attributes => attr_names)
       end
     end
diff --git a/activemodel/lib/active_model/validations/inclusion.rb b/activemodel/lib/active_model/validations/inclusion.rb
index d42c95357c..a122e9e737 100644
--- a/activemodel/lib/active_model/validations/inclusion.rb
+++ b/activemodel/lib/active_model/validations/inclusion.rb
@@ -1,6 +1,11 @@
 module ActiveModel
   module Validations
     class InclusionValidator < EachValidator
+      def check_validity!
+         raise ArgumentError, "An object with the method include? is required must be supplied as the " <<
+                              ":in option of the configuration hash" unless options[:in].respond_to?(:include?)
+       end
+
       def validate_each(record, attribute, value)
         return if options[:in].include?(value)
         record.errors.add(attribute, :inclusion, :default => options[:message], :value => value)
@@ -30,10 +35,6 @@ module ActiveModel
       def validates_inclusion_of(*attr_names)
         options = attr_names.extract_options!
         options[:in] ||= options.delete(:within)
-
-        raise ArgumentError, "An object with the method include? is required must be supplied as the " <<
-                             ":in option of the configuration hash" unless options[:in].respond_to?(:include?)
-
         validates_with InclusionValidator, options.merge(:attributes => attr_names)
       end
     end
diff --git a/activemodel/lib/active_model/validations/length.rb b/activemodel/lib/active_model/validations/length.rb
index 66b2ae5b18..1214c5f4bf 100644
--- a/activemodel/lib/active_model/validations/length.rb
+++ b/activemodel/lib/active_model/validations/length.rb
@@ -1,16 +1,24 @@
 module ActiveModel
   module Validations
     class LengthValidator < EachValidator
-      MESSAGES = { :is => :wrong_length, :minimum => :too_short, :maximum => :too_long }.freeze
-      CHECKS   = { :is => :==, :minimum => :>=, :maximum => :<= }.freeze
+      OPTIONS   = [ :is, :within, :in, :minimum, :maximum ].freeze
+      MESSAGES  = { :is => :wrong_length, :minimum => :too_short, :maximum => :too_long }.freeze
+      CHECKS    = { :is => :==, :minimum => :>=, :maximum => :<= }.freeze
 
+      DEFAULT_TOKENIZER = lambda { |value| value.split(//) }
       attr_reader :type
 
       def initialize(options)
-        @type = options.delete(:type)
+        options[:tokenizer] ||= DEFAULT_TOKENIZER
         super
+        @type = (OPTIONS & options.keys).first
       end
 
+      def check_validity!
+        ensure_one_range_option!
+        ensure_argument_types!
+      end
+        
       def validate_each(record, attribute, value)
         checks = options.slice(:minimum, :maximum, :is)
         value  = options[:tokenizer].call(value) if value.kind_of?(String)
@@ -34,11 +42,35 @@ module ActiveModel
           record.errors.add(attribute, MESSAGES[key], :default => custom_message, :count => check_value) unless valid_value
         end
       end
+
+    protected
+
+      def ensure_one_range_option! #:nodoc:
+        range_options = OPTIONS & options.keys
+
+        case range_options.size
+        when 0
+          raise ArgumentError, 'Range unspecified. Specify the :within, :maximum, :minimum, or :is option.'
+        when 1
+          # Valid number of options; do nothing.
+        else
+          raise ArgumentError, 'Too many range options specified. Choose only one.'
+        end
+      end
+    
+      def ensure_argument_types! #:nodoc:
+        value = options[type]
+
+        case type
+        when :within, :in
+          raise ArgumentError, ":#{type} must be a Range" unless value.is_a?(Range)
+        when :is, :minimum, :maximum
+          raise ArgumentError, ":#{type} must be a nonnegative Integer" unless value.is_a?(Integer) && value >= 0
+        end
+      end
     end
 
     module ClassMethods
-      ALL_RANGE_OPTIONS = [ :is, :within, :in, :minimum, :maximum ].freeze
-      DEFAULT_TOKENIZER = lambda { |value| value.split(//) }
 
       # Validates that the specified attribute matches the length restrictions supplied. Only one option can be used at a time:
       #
@@ -78,28 +110,6 @@ module ActiveModel
       def validates_length_of(*attr_names)
         options = { :tokenizer => DEFAULT_TOKENIZER }
         options.update(attr_names.extract_options!)
-
-        # Ensure that one and only one range option is specified.
-        range_options = ALL_RANGE_OPTIONS & options.keys
-        case range_options.size
-        when 0
-          raise ArgumentError, 'Range unspecified. Specify the :within, :maximum, :minimum, or :is option.'
-        when 1
-          # Valid number of options; do nothing.
-        else
-          raise ArgumentError, 'Too many range options specified. Choose only one.'
-        end
-
-        type  = range_options.first
-        value = options[type]
-
-        case type
-        when :within, :in
-          raise ArgumentError, ":#{type} must be a Range" unless value.is_a?(Range)
-        when :is, :minimum, :maximum
-          raise ArgumentError, ":#{type} must be a nonnegative Integer" unless value.is_a?(Integer) && value >= 0
-        end
-
         validates_with LengthValidator, options.merge(:attributes => attr_names, :type => type)
       end
 
diff --git a/activemodel/lib/active_model/validations/numericality.rb b/activemodel/lib/active_model/validations/numericality.rb
index 8ffa395a2d..914a3133cf 100644
--- a/activemodel/lib/active_model/validations/numericality.rb
+++ b/activemodel/lib/active_model/validations/numericality.rb
@@ -1,56 +1,64 @@
 module ActiveModel
   module Validations
     class NumericalityValidator < EachValidator
-      CHECKS = { :greater_than => '>', :greater_than_or_equal_to => '>=',
-                 :equal_to => '==', :less_than => '<', :less_than_or_equal_to => '<=',
-                 :odd => 'odd?', :even => 'even?' }.freeze
+      CHECKS = { :greater_than => :>, :greater_than_or_equal_to => :>=,
+                 :equal_to => :==, :less_than => :<, :less_than_or_equal_to => :<=,
+                 :odd => :odd?, :even => :even? }.freeze
+
+      def check_validity!
+        options.slice(*CHECKS.keys) do |option, value|
+          next if [:odd, :even].include?(option)
+          raise ArgumentError, ":#{option} must be a number, a symbol or a proc" unless value.is_a?(Numeric) || value.is_a?(Proc) || value.is_a?(Symbol)
+        end
+      end
 
       def validate_each(record, attr_name, value)
         before_type_cast = "#{attr_name}_before_type_cast"
 
-        if record.respond_to?(before_type_cast.to_sym)
-          raw_value = record.send("#{attr_name}_before_type_cast") || value
-        else
-          raw_value = value
-        end
+        raw_value = record.send("#{attr_name}_before_type_cast") if record.respond_to?(before_type_cast.to_sym)
+        raw_value ||= value
 
-        return if options[:allow_nil] and raw_value.nil?
+        return if options[:allow_nil] && raw_value.nil?
 
-        if options[:only_integer]
-          unless raw_value.to_s =~ /\A[+-]?\d+\Z/
-            record.errors.add(attr_name, :not_a_number, :value => raw_value, :default => options[:message])
-            return
-          end
-          raw_value = raw_value.to_i
-        else
-          begin
-            raw_value = Kernel.Float(raw_value)
-          rescue ArgumentError, TypeError
-            record.errors.add(attr_name, :not_a_number, :value => raw_value, :default => options[:message])
-            return
-          end
+        unless value = parse_raw_value(raw_value, options)
+          record.errors.add(attr_name, :not_a_number, :value => raw_value, :default => options[:message])
+          return
         end
 
         options.slice(*CHECKS.keys).each do |option, option_value|
           case option
           when :odd, :even
-            unless raw_value.to_i.method(CHECKS[option])[]
-              record.errors.add(attr_name, option, :value => raw_value, :default => options[:message])
+            unless value.to_i.send(CHECKS[option])
+              record.errors.add(attr_name, option, :value => value, :default => options[:message])
             end
           else
-            option_value = option_value.call(record)        if option_value.is_a? Proc
-            option_value = record.method(option_value).call if option_value.is_a? Symbol
-            
-            unless raw_value.method(CHECKS[option])[option_value]
-              record.errors.add(attr_name, option, :default => options[:message], :value => raw_value, :count => option_value)
+            option_value = option_value.call(record) if option_value.is_a?(Proc)
+            option_value = record.send(option_value) if option_value.is_a?(Symbol)
+
+            unless value.send(CHECKS[option], option_value)
+              record.errors.add(attr_name, option, :default => options[:message], :value => value, :count => option_value)
             end
           end
         end      
       end
+
+    protected
+
+      def parse_raw_value(raw_value, options)
+        if options[:only_integer]
+          raw_value.to_i if raw_value.to_s =~ /\A[+-]?\d+\Z/
+        else
+          begin
+            Kernel.Float(raw_value)
+          rescue ArgumentError, TypeError
+            nil
+          end
+        end
+      end
+
     end
+
     module ClassMethods
-
-
       # Validates whether the value of the specified attribute is numeric by trying to convert it to
       # a float with Kernel.Float (if <tt>only_integer</tt> is false) or applying it to the regular expression
       # <tt>/\A[\+\-]?\d+\Z/</tt> (if <tt>only_integer</tt> is set to true).
@@ -93,14 +101,6 @@ module ActiveModel
       def validates_numericality_of(*attr_names)
         options = { :only_integer => false, :allow_nil => false }
         options.update(attr_names.extract_options!)
-
-        numericality_options = NumericalityValidator::CHECKS.keys & options.keys
-
-        (numericality_options - [ :odd, :even ]).each do |option|
-          value = options[option]
-          raise ArgumentError, ":#{option} must be a number, a symbol or a proc" unless value.is_a?(Numeric) || value.is_a?(Proc) || value.is_a?(Symbol)
-        end
-
         validates_with NumericalityValidator, options.merge(:attributes => attr_names)
       end
     end
diff --git a/activemodel/lib/active_model/validator.rb b/activemodel/lib/active_model/validator.rb
index 6885c6800e..342c4691ff 100644
--- a/activemodel/lib/active_model/validator.rb
+++ b/activemodel/lib/active_model/validator.rb
@@ -70,6 +70,7 @@ module ActiveModel #:nodoc:
     def initialize(options)
       @attributes = options.delete(:attributes)
       super
+      check_validity!
     end
 
     def validate(record)
@@ -83,5 +84,8 @@ module ActiveModel #:nodoc:
     def validate_each(record)
       raise NotImplementedError
     end
+
+    def check_validity!
+    end
   end
 end