Albert G. Mackey writes on the allegorical nature of Masonic symbols.
Albert G. Mackey, An Encyclopaedia of Freemasonry and Its Kindred Sciences (Philadelphia: Moss & Company, 1874), 56
Allegory. A discourse or narrative in which there is a literal and a figurative sense, a patent and a connected meaning; the literal or patent sense being intended, by analogy or comparison, to indicate the figurative or concealed one. . . . All the legends of Freemasonry are more or less allegorical, and whatever truth there may be in some of them in a historical point of view, it is only as allegories or legendary symbols that they are of importance. The English lectures have therefore very properly defined Freemasonry to be "a system of morality veiled in allegory and illustrated by symbols."