> Yes but you can't discount that. In terms of guiding what we should do now it can and should be discounted to zero. > Another example: cycling is only a via

> Yes but you can't discount that. In terms of guiding what we should do now it can and should be discounted to zero. > Another example: cycling is only a viable means of transport because of the extensive road network built for (and by!) oil-powered vehicles. Another example of what? Of one technology being dependant on the history and environment that preceded it? Isn't that true for everything? As to the specifics of your example : you know that bicycles were popular before cars don't you? 'Bicycles and horse buggies were the two mainstays of private transportation just prior to the automobile' From http://en.wikipedia.org/wiki/Bicycle http://en.wikipedia.org/wiki/Bicycle