That there is such real being, apart from the “thought”-being whereby the mind is constituted formally knowing, is proved elsewhere; as also that this _esse intentionale_ has modes which cannot be attributed to the _esse reale_. We merely note these points here in order to indicate the errors involved in the opposite contentions. Our concepts are characterized by abstractness, by a consequent static immutability, by a plurality often resulting from purely mental distinctions, by a universality which transcends those distinctions and unifies the variety of all subordinate concepts in the widest concept of _being_. Now if, for example, we attribute the unifying mental mode of universality to real being, we must draw the pantheistic conclusion that all real being is one: the logical outcome of extreme realism. If, again, we transfer purely mental distinctions to the unity of the Absolute or Supreme Being, thus making them real, we thereby deny infinite perfection to the most perfect being conceivable: an error of which some catholic philosophers of the later middle ages have been accused with some foundation. If, finally, we identify the _esse reale_ with the _esse intentionale_, and this with the thought-process itself, we find ourselves at the starting-point of Hegelian monism.(68) 5. FUNDAMENTAL DISTINCTIONS IN REAL BEING.—Leaving logical and ideal being aside, and fixing our attention exclusively on real being, we may indicate here a few of the most fundamental distinctions which experience enables us to recognize in our study of the universal order of things. (_a_) _Possible or Potential Being and Actual Being._—The first of these distinctions is that between possibility and actuality, between that which can be and that which actually is. For a proper understanding of this distinction, which will be dealt with presently, it is necessary to note here the following divisions of _actual_ being, which will be studied in detail later on. (_b_) _Infinite Being and Finite Beings._—All people have a sufficiently clear notion of Infinite Being, or Infinitely Perfect Being: though not all philosophers are agreed as to how precisely we get this notion, or whether there actually exists such a being, or whether if such being does exist we can attain to a certain knowledge of such existence. By infinite being we mean a being possessing all conceivable perfections in the most perfect conceivable manner; and by finite beings all such beings as have actually any conceivable limitation to their perfection. About these nominal definitions there is no dispute; and scholasticism identifies their respective objects with _God_ and _creatures_.