diff --git a/smocore/include/mentalExistent.h b/smocore/include/mentalExistent.h
index af8d5a6..8ad6748 100644
--- a/smocore/include/mentalExistent.h
+++ b/smocore/include/mentalExistent.h
@@ -11,9 +11,13 @@ namespace smo {
  * Mentexents are Mentities, but not all Mentities are Mentexents.
  */
 
-class MentalExistent
+struct MentalExistent
 : public MentalEntity
 {
+public:
+	MentalExistent(const MentalEntity::Id id)
+	: MentalEntity(id)
+	{}
 };
 
 typedef MentalExistent Mentexent;
diff --git a/smocore/include/quale.h b/smocore/include/quale.h
index 0c939ef..e9886e6 100644
--- a/smocore/include/quale.h
+++ b/smocore/include/quale.h
@@ -11,21 +11,10 @@ class Quale
 : public MentalExistent
 {
 public:
-	enum class Type
-	{
-		NEUTRAL,
-		/* Bounding refers to qualia such as tactile pressure which
-		 * are mostly neutral but disclose information about the limits
-		 * of the body.
-		 **/
-		BOUNDING,
-		PAINFUL,
-		PLEASURABLE
-	} type;
-
-public:
-	Quale(const Type type, const int32_t intensity)
-	: type(type), intensity(intensity) {}
+	Quale(const MentalEntity::Id id, const int32_t intensity)
+	: MentalExistent(id),
+		intensity(intensity)
+	{}
 
 public:
 	int32_t intensity;
@@ -36,6 +25,15 @@ class NeutralQuale
 {
 };
 
+/* Bounding qualia refer to qualia such as tactile pressure which are
+ * mostly neutral but disclose information about the limits of the body.
+ * These qualia are supplied by interoceptive sensors.
+ **/
+class BoundingQuale
+: public NeutralQuale
+{
+};
+
 class NonNeutralQuale
 : public Quale, public AttentionTrigger
 {