We often think of ourselves as living in a world which no longer has any unexplored frontiers. We speak of pioneering as a thing of the past. 

 

But in doing so we forget that the greatest adventure still challenges us - what Mister Justice Holmes called "the adventure of the human mind." Men may be hemmed in geographically, but every generation stands on the frontiers of the mind. 

In the world of ideas, there is always pioneering to be done, and it can be done by anyone who will use the equipment with which he or she is endowed. The great ideas belong to everyone. 
- Mortimer J. Alder