[tmzt]

This might be a better one, from the US Constitution:

  To promote the progress of science and useful arts, by
  securing for limited times to authors and inventors the
  exclusive right to their respective writings and discoveries;

http://www.law.cornell.edu/constitution/articlei#section8

[peterashford]

When do you think patents were first envisaged? Hint: it's a little bit earlier than the existence of the US

[hackinthebochs]

The basis for patents in US law is the only thing relevant to this conversation.