Legal writing is replete with antiquated and needless words and phrases. “In witness whereof” often is one such phrase. You will see it at the end of business contracts: “In witness whereof, the parties have executed this agreement on [such and such date].”
“Witness” suggests a formal attestation or vouching of something, such as a signature or the terms of the contract. “Whereof” in this context means “of what” or “of which”. Thus, “in witness whereof” essentially means to attest to something in the document being signed.
In some cases, a formal attestation is appropriate and a government form will mandate the use of the “in witness whereof” verbiage to convey such attestation (such as in notarized documents). But in most business documents between private parties, “in witness whereof” is stuffy and meaningless. The parties do not “witness” each other’s signature or the terms of the agreement. The parties merely sign it and date it, and thereby demonstrate in writing their agreement to the terms of the contract.
A business contract should capture the essential terms of the agreement using clear, readable language. Omitting archaic and useless phrases is a good place to start.
