Little is known of the early life of Andrew Donaldson, an eccentric but deeply sincere man believed to have been born at Auchtertool and originally educated for the ministry. Limited means led him to become a grammar-school master at Dunfermline, though intense study—particularly of Greek and Hebrew—was thought to have impaired his mind, and he soon resigned the post. Embracing extreme simplicity, he adopted the appearance and habits of a biblical prophet, refusing to shave, living austerely, and rejecting social conventions he viewed as sinful or excessive. Despite his striking appearance and singular opinions, he was gentle, kind, and scrupulously charitable, never repeating unkind remarks about others. Known for his literal adherence to Scripture, his wit, and his quiet integrity, he lived a solitary life, spending his final years in Dunfermline, where he died in 1793, remembered as a learned man and sincere Christian.