I think it should really be a personal decision. Maybe you're luckier than he is in other ways. Maybe he'll create something great by using the knowledge which

I think it should really be a personal decision. Maybe you're luckier than he is in other ways. Maybe he'll create something great by using the knowledge which will benefit everybody. Maybe he can't buy the book at all, so downloading might not have that bad an effect. I personally feel all creative content should be through some sort of a rental model (e.g. pay per view) that takes into account lots of different details like affordability, amount of use, importance, relative importance to other content etc. In this way, if I still get to keep every book on the planet, but if I just spent a few seconds on it browsing the pages, I'm not really going to get charged for it. Although, a lot of popular books make money because of their popularity and the big names associated with them and not because they get read so much.