What are the 3 greater lights and 3 lesser lights in Freemasonry? And what are their significations?

The three greater lights are the Holy Bible, the Square, and the Compasses, presented in conjunction with the Square and Compasses resting upon the Bible as their base 3. The three lesser lights signify the Sun, the Moon, and the Master of the Lodge 23.

In early Masonic catechisms, such as W. Finch's 1802 account, the lesser lights are physically described as three illuminated candles positioned in the East, South, and West to light Masons to, at, and from labor 1. Symbolically, Mackey explains that just as the sun rules the day and the moon governs the night, the Master is symbolized by the sun in his duty to rule and govern the lodge with equal regularity and precision 2. This governance extends across the lodge's three principal officers, with the Master in the East representing the rising sun, the Junior Warden in the South the meridian sun, and the Senior Warden in the West the setting sun 2.

Wilmshurst offers a psychological reading, interpreting the greater lights as the fundamental essences and spiritual realities of the candidate's undeveloped nature 3. In his view, the lesser lights represent the candidate's finite intellect and perceptive faculties—the necessary subjective instrument through which he is enabled to contemplate the objective truths represented by the greater lights 3. While later authorities classify the Sun, Moon, and Master as the lesser lights 23, Finch's 1802 text applies the phrasing of the great lights directly to the triad of the Sun, Moon, and Master Mason 1.