Why and wherefore are synonyms that are often used interchangeably to indicate a reason or a cause. However, there are several other synonyms that can be used in place of these words. For instance, the word 'cause' refers to the reason that leads to a particular outcome or action. Additionally, the term 'motive' is a synonym that refers to the inner drive or intention that motivates someone to act in a particular way. 'Purpose' is another synonym that refers to the reason why something is done or created. Lastly, 'rationale' is a synonym that refers to the logical basis behind a particular decision or action. Overall, there are many words that are synonymous with 'why and wherefore', and using them in writing or speech can add variety and clarity to the communication.