Not much more than a quarter of a century ago the word “animism” began to be used to describe that particular phase of the psychological condition of primitive peoples by which they believe that a spirit (anima) resides in everything, material and immaterial. This spirit is generally closely associated with the thing itself, sometimes actually identified with it. When it is thought of as distinct from the thing, it is supposed to have the form of the thing, to be in a word its “double.” These doubles exercise an influence, often for evil, over the thing, and it is expedient and necessary therefore that they should be propitiated so that their evil influence may be removed and the thing itself may prosper. These doubles are not as yet gods, they are merely powers, potentialities, but in the course of time they develop into gods. The first step in this direction is the obtaining of a name, a name the knowledge of which gives a certain control over the power to him who knows it. Finally these powers equipped with a name begin to take on personal characteristics, to be thought of as individuals, and finally represented under the form of men.
It cannot be shown that all the gods of Rome originated in this way, but certainly many of them did, and it is not impossible that they all did; and this theory of their origin explains better than any other theory certain habits of thought which the early Romans cherished in regard to their gods. At the time when our knowledge of Roman religion begins, Rome is in possession of a great many gods, but very few of them are much more than names for powers. They are none of them personal enough to be connected together in myths. And this is the very simple reason why there was no such thing as a native Roman mythology, a blank in Rome’s early development which many modern writers have refused to admit, taking upon themselves the unnecessary trouble of positing an original mythology later lost. The gods of early Rome were neither married nor given in marriage; they had no children or grandchildren and there were no divine genealogies. Instead they were thought of occasionally as more or less individual powers, but usually as masses of potentialities, grouped together for convenience as the “gods of the country,” the “gods of the storeroom,” the “gods of the dead,” etc. Even when they were conceived of as somewhat individual, they were usually very closely associated with the corresponding object, for example Vesta was not so much the goddess of the hearth as the goddess “Hearth” itself, Janus not the god of doors so much as the god “Door.”