How did operative masonry become speculative?

The transition from operative building to speculative Freemasonry occurred as non-handicraft members—scholars, gentlemen, and students—were admitted into existing operative lodges 13. These non-operatives were accepted into the Craft without undertaking a traditional seven-year apprenticeship or engaging in physical construction 3. Even within early guild masonry, working tool symbolism and moral instruction were integrated into lodge ceremonies, laying the groundwork for philosophical expansion 1. As cathedral building declined following the Reformation, the proportion of these "Accepted Masons" steadily increased until they became the majority in many lodges 3.

In Scottish lodges such as the Lodge of Edinburgh (Mary's Chapel) No. 1, operative stonemasons were designated as "Domatic" Masons, while non-craftsmen were termed "Geomatic" or "Theorical" Masons 2. Operatives guarded their trade status, maintaining distinct classifications and observing ceremonial differences because non-professionals could not fulfill the practical trade tests required of working craftsmen 2. According to historical records published by the United Grand Lodge of England, organized speculative governance emerged in 1717 with the formation of the Premier Grand Lodge in London, cementing the shift from operative guilds to a symbolic fraternity.

Through this gradual shift, lodges evolved into purely moral and allegorical institutions, retaining the traditional tools, trade terms, and structural hierarchy of the medieval operative masons to convey ethical teachings 13.

The websites I drew on here are not among those a Masonic researcher would ordinarily rely upon. Please weigh what they say accordingly.