Every time we study something specific, we are also studying the world as a whole. The metaphysician knows this; others who are not aware of the extent of their metaphysical proclivities, do not know this.
The study of the world, or reality, can be taken as one, or divided. Taken as one, this study is philosophy or metaphysics. Taken as divided, it is all the other sciences and arts. All study has metaphysics as a base, even when we don’t know of this base.
The study of the world is the study of things. All things taken together are the world. Things, as I have shown, appear in different ways; take different forms. These ways or forms are themselves things.
All things, too, are eternally and immediately in a relation of being alike and being different. Are there any ways, or is there any way, in which all things are alike? It would seem that if all things are things, they would have thingness in common; or they would be called something else. The world can be called a Great Thingdom.
Things, then, have thingness in common. Thingness is reality; in fact, the word thingness is, in terms of its Anglo-Saxon source, what reality is, in terms of its Latin source.
Therefore, if reality is common to all things, the study of reality as such is of metaphysics.
The next way things can be seen—next after their being seen just as things, or real—is that they are and that they change. The word are is related to the rest aspect of things; the word change, of course, to the motion.
The word change is seen here as that which makes a thing other than it is.
The question is, then, do all things have being and change in common—that is, can it be said that all things are and that they change? This question, presented in some detail, can be subdivided in questions like these: Is dew, and does it change; is justice, and does it change; is the number 3, and does it change; is a tire, and does it change; is the 15th century, and does it change; is love, and does it change?
If all things are and all things change, then what being is and what change is are likewise of metaphysics.
Then, when a thing is and changes—anything and all things—what else must it be, and have?
Is it one thing? Can it be seen in more than one way? Is it the same as other things? Is it different? Is it a whole? Is it a part? Is it substance? Is it form? Is it a cause? Is it an effect? Is it in time? Is it in space? Is it known? Is it not known?
If the answer to all these questions is, Yes—and I think it is—then oneness, manyness, sameness, difference, wholeness, partness, substance, form, cause, effect, time, space, knownness, and unknownness—since they are things all things have in common, are, like reality itself, the field or subject of metaphysics. What other things we may see as belonging to all things, likewise are in the metaphysical field.