Marsilio Ficino’s Platonic Theology, Volume II

Seventh argument: because it has its being in its own essence.

1We call one thing essence and another being. By essence we mean the account of a thing that is comprehended in its definition. Being, however, is the act of that essence and a certain presence of it in the natural world. Take the example of a comet. The essence of a comet is its account and definition: a dry vapor in the upper air, kindled by fire and circling through the air in an ordered course. This definition is true today even if no comet shines anywhere today. But for a comet of this kind to have being means that the cometary nature which the definition designates day after day is now actually shining somewhere. Such being cannot occur without a determinate place and time, for the essence becomes present only here or there, at this hour or that. Thus the being of natural things requires a determinate place and time; their essence does not. The account of the comet remains true even if no comet is now aflame anywhere. Indeed, if its definition included a determinate time and place—say, here today or there tomorrow—then all comets would have to exist together in the same hour and the same region of the sky in which one comet exists. For in every comet there is the common essence of a comet and the same account. If that account were bound to a determinate place and time, all comets would be bound to the same limits of place and time, just as rational capacity, because it is included in the definition of man, belongs to every man. Essence and being in natural things therefore differ in this: being is bound to a determinate place and time, whereas essence, so far as lies in itself, is equally disposed toward almost every time and every place. Humanity itself can subsist no less in other ages than in ours, and no less in the East than in the West. Plato and Socrates, however, need this place or that and this time or that in order to be and to live. Essence is denoted in humanity itself; being is discerned in these individual men. Essence is therefore excluded from every particular limit of time and place. By its own nature it needs no place in order to be preserved, nor does it have temporal bounds that may one day be overstepped, since it is exempt from bounds of that kind. It flourishes, therefore, everywhere and always. Every essence, considered in itself, is thus called immortal; and such by its nature is the essence of every form.