The point within the circle was the beginning of the process in which the King's Master Mason, overseeing and managing the building of a great Cathedral, tried the squares of the workmen that they might be true ninety degree angles.
Every school boy knows the simple geometrical demonstration, but in days when only the few could read and write, this was the great secret -
It was thus that the King's Master Mason tested the wooden squares of his stone Masons. Originally, "While a Mason kept his tools circumscribed by the point and circle, they could not materially err". Today the line across has become two; we have added the Holy Saints John and the Holy Scriptures and we now circumscribe our passions and not out tools, thus losing the old significance of the symbol. but the meaning is still there; the symbol behind the symbol is the need of true tools for our work, whether the tools be of wood and metal for labor upon material, or for work upon the affairs of life.
In other words, the symbol behind the symbol is the need for standards known to be correct to which to hew, and a right pattern to follow during all of Masonic life.