Founding on is a phrase that refers to the basis or rationale of an idea or concept. There are multiple synonyms that can be used in place of this phrase, depending on the context of the sentence. Examples include beginning with, rooted in, based upon, established upon, originating from, originating in, forged from, deriving from, stemming from, and grounded in. The use of synonyms not only enhances the variety and depth of language but also assists in the reader's understanding of the text, allowing them to grasp the author's intent without repetition. Therefore, utilizing synonyms for "founding on" can aid in the overall clarity and effectiveness of one's writing.