Scottish operative lodges began in the seventeenth century to admit non-operative members as accepted or gentleman masons and that by the early eighteenth century in some lodges the accepted or gentleman masons had gained the ascendancy: those lodges became, in turn speculative lodges, whilst others continued their purely operative nature. The speculative lodges eventually combined to form the Grand Lodge of Scotland in 1736.
The Craft: A History of English Freemasonry (ed. HarperCollins, 1986)