Freemasonry describes itself as a "beautiful system of morality, veiled in allegory and illustrated by symbols". The symbolism is mainly, but not exclusively, drawn from the tools of stonemasons – the square and compasses, the level and plumb rule, the trowel, the rough and smooth ashlars, among others. Moral lessons are attributed to each of these tools, although the assignment is by no means consistent. The meaning of the symbolism is taught and explored through ritual, and in lectures and articles by individual Masons who offer their personal insights and opinions.