6. Difference between Logic and Metaphysics. -- Another science, having all being for its object, also deserves to be called a general science; because it rules all knowledge: this is metaphysics. Metaphysics and logic are both concerned with all being (common material object), but under different aspects (proper formal object). The object of metaphysics is real being considered formally in its real quiddity, invested with real attributes.

Logic has for its object the same being, formally considered in its mental objectivity, invested with attributes of reason which it acquires in thought and in virtue of thought.

Everything real (existing or possible) is intelligible. Now the real, when it becomes the object of a mental conception, inevitably participates in the attributes which are inherent in the evercise of thought: as a mental object, it becomes abstract and urnversal. Between abstract, universal objects relations are established which under the concrete and particular conditions of existent things are impossible: such a mental object becomes the attribute of another object of thought which plays tlie part of subect in regard to the former; the content and extension of ideas give rise to relations of identity or of exclusion; judgments are produced, chains of reasoning are forged, and all the while the material of these various intellectual operations is being, not real being, independent of thought, but the being of reason, i. e., being under the aspect and with the characteristics which mental conception communicates to it.

Metaphysics is the universal science of the real.

Logic is the science of the science of the real.^{1}

{1} The relations considered by this philosophical discipline are not the ontological relations upon which the attention of the mind falls immediately, the primae intentiones, objects of a first abstraction, but the logical relations springing from the combination of abstract objects to which the reason reflecting returns, secundae intentiones, objects of second abstraction.