Having eliminated these and other loan-gods, we find that the genuine Italian deities which remain fall into two classes. The one class consists of such abstractions as Forculus, the spirit of doors; Cardea, that of hinges; Limentinus, that of the threshold, &c., which can scarcely be dignified by the name of gods, but are rather spirits, and amply warrant Chantepie de la Saussaye's remark that Roman religion was still steeped in animism.[3] The other class includes such gods as Janus, Jupiter, Mars, Diana, Venus, Hercules, &c. It is necessary to note, however, that the worship even of these gods can be proved to have been considerably Hellenised in historic times:[4] some of their ritual and all their mythology was borrowed from Greece, as we shall subsequently see. And when the loan-myths and loan-cults have been removed, the genuine Italian gods stand forth essentially and fundamentally different from those of Greece.[5] Here, too, we may note that if comparative mythologists adhere to their principle of not identifying the gods of different nations, unless their names can be shown by comparative philology to be identical, they must admit that Mars and Ares, Venus and Aphrodite, Diana and Artemis, Juno and Hera, and all the other pairs of deities which the ancients identified, are, with the sole exception of Jupiter and Zeus and of Vesta and Hestia, not of cognate but of diverse origin. In fine, the differences between Greek and Italian gods are fundamental and original: the resemblances can be shown to be due to borrowing in historic times. There is, however, one of the great Roman gods who was never identified with any Hellenic deity, Janus. Now, although Janus ranks with Jupiter and Mars in the Roman system as an indubitable god, yet in origin and function he is not to be distinguished from those inferior, animistic powers to whom the title of spirit is the highest that can be assigned. Janus is the spirit that resides in or presides over door-openings (_ianus_, _ianua_), just as Forculus has to do with doors (_fores_), Limentinus with the threshold (_limen_), and Cardea with the hinges (_cardo_). He is also the "spirit of opening,"[6] who was to be invoked at the commencement of every act. Plutarch's questions why he should be represented with two heads, and why the year should begin with the month named after him, January (_R. Q._, 22 and 19), are thus at once explained: "The double-head looking both ways was connected with the gate that opened both ways;" and in January, "after the rest of the middle of winter, the cycle of the labours of the field began afresh."[7]