diff --git a/app/controllers/comments_controller.rb b/app/controllers/comments_controller.rb
index bbad3ca3b..3854ff07f 100644
--- a/app/controllers/comments_controller.rb
+++ b/app/controllers/comments_controller.rb
@@ -1,12 +1,11 @@
 class CommentsController < ApplicationController
-  before_action :authenticate_user!
-  before_action :set_debate, :set_parent, only: :create
+  before_action :build_comment, only: :create
+  load_and_authorize_resource
   respond_to :html, :js
 
   def create
-    @comment = Comment.build(@debate, current_user, params[:comment][:body])
     @comment.save!
-    @comment.move_to_child_of(@parent) if reply?
+    @comment.move_to_child_of(parent) if reply?
 
     Mailer.comment(@comment).deliver_now if email_on_debate_comment?
     Mailer.reply(@comment).deliver_now if email_on_comment_reply?
@@ -15,7 +14,6 @@ class CommentsController < ApplicationController
   end
 
   def vote
-    @comment = Comment.find(params[:id])
     @comment.vote_by(voter: current_user, vote: params[:value])
     respond_with @comment
   end
@@ -25,16 +23,20 @@ class CommentsController < ApplicationController
       params.require(:comments).permit(:commentable_type, :commentable_id, :body)
     end
 
-    def set_debate
-      @debate = Debate.find(params[:debate_id])
+    def build_comment
+      @comment = Comment.build(debate, current_user, params[:comment][:body])
     end
 
-    def set_parent
-      @parent = Comment.find_parent(params[:comment])
+    def debate
+      @debate ||= Debate.find(params[:debate_id])
+    end
+
+    def parent
+      @parent ||= Comment.find_parent(params[:comment])
     end
 
     def reply?
-      @parent.class == Comment
+      parent.class == Comment
     end
 
     def email_on_debate_comment?
@@ -42,6 +44,6 @@ class CommentsController < ApplicationController
     end
 
     def email_on_comment_reply?
-      reply? && @parent.author.email_on_comment_reply?
+      reply? && parent.author.email_on_comment_reply?
     end
-end
\ No newline at end of file
+end
diff --git a/app/models/ability.rb b/app/models/ability.rb
index 3946e5f53..c1fc24ae3 100644
--- a/app/models/ability.rb
+++ b/app/models/ability.rb
@@ -13,6 +13,8 @@ class Ability
         debate.editable_by?(user)
       end
 
+      can [:create, :vote], Comment
+
       if user.moderator? or user.administrator?
 
       elsif user.administrator?
diff --git a/spec/models/ability_spec.rb b/spec/models/ability_spec.rb
index 220db821d..3954ec600 100644
--- a/spec/models/ability_spec.rb
+++ b/spec/models/ability_spec.rb
@@ -24,6 +24,9 @@ describe Ability do
     it { should be_able_to(:show, user) }
     it { should be_able_to(:edit, user) }
 
+    it { should be_able_to(:create, Comment) }
+    it { should be_able_to(:vote, Comment) }
+
     describe "other users" do
       let(:other_user) { create(:user) }
       it { should_not be_able_to(:show, other_user) }