All Trekkies (well, most people in general) are acquainted with the Vulcan phrase/salute 'live long and prosper'. Now Vulcans, following Surak, based their society on logic, hence it seems logical to conclude that such an integral phrase in their society as this would be logical (logic!).
However, there do exist logical arguments against having long life (especially) and prosperity. For example; a longer life means there is increased chance of developing debilitating illnesses (for example when Sarek developed Bendii Syndrome). In terms of prosperity (from a wealth perspective) one can easily become obsessed with monetary wealth and miss the more important meanings in life (although I do concede that this doesn't necessarily apply to a logical Vulcan, but to other species like humans who have a history full of money corrupting).
My question: is it explained in any canonical source why Vulcans consider it to be logical to live long and prosper (i.e. what arguments do they base this strong conviction on)?