If my definition of 'value' was something that was totally contingent on both post-industrial society and an ultracapitalist approach to production, and it made me deduce that human being's lives over thousands of years or in other societies were worth "nothing", I think I would interpret this as a 'reductio-ad-absurdum'. That is, by deducing an absurd conclusion from the premise, that makes a strong argument that my definition of 'value' must be so narrow as to be effectively broken. I would respond by looking for a different, more wide definition of value, among the various ones that have been proposed.