The properties of the stone of Tara were oracular; and the stone itself was one of a large class of stones endowed in popular opinion with divining powers, and actually resorted to for the purpose of enquiry. When the reputation of an oracle is once established, it is consulted for many purposes. Not only political, but juridical and domestic purposes are enumerated by the author of the Colloquy in regard to the _Lia Fáil_. Among these functions is the recognition of the monarch. The phrase used in the Colloquy is ambiguous. It is not stated why, or on what occasion, the stone was expected to make its voice heard. In practice the only object of obtaining such a recognition would be that of determining the succession to the throne. Keating supplies the missing explanation. “It was a stone,” he says, “on which were enchantments, for it used to roar under the person who had the best right to obtain the sovereignty of Ireland at the time of the men of Ireland being in assembly at Tara to choose a king over them.”[293.2] Whether as a matter of fact the stone ever was consulted with this object is another question. It is enough at {294} present to know that Irish tradition asserted this use of the oracle. In a semi-civilized community a disputed succession is of frequent occurrence. To prevent a dispute, and to settle it when it arises, various means are adopted. The usual Irish plan seems to have been the custom of Tanistry. “During the lifetime of a chief,” Sullivan tells us, “his successor was elected under the name of _Tanaiste_; and on the death of the former the latter succeeded him. The _Tanaiste_ was not necessarily the son of the chief: he might be his brother or nephew; but he should belong to his _Fine_,” or family.[294.1]