"Simple soul" is a term used to describe someone who is uncomplicated, genuine, and honest. There are several synonyms for this phrase, including "innocent," "naive," "unsophisticated," "guileless," and "unpretentious." These words emphasize the purity and sincerity that a simple soul possesses, as well as their lack of malice or ulterior motives. Another synonymous term is "down-to-earth," which highlights a simple soul's grounded and practical nature, while "unassuming" stresses their humble and modest demeanor. Finally, "childlike" describes a simple soul's unjaded and open-minded approach to life, where wonder and curiosity reign supreme. Overall, these synonyms capture the essence of what it means to be a "simple soul".