Donald Griffin quotes

The investigation of the possibility that animals might think in terms of concepts and even categories of important objects has been seriously impeded because comparative psychologists have seemed to be almost petrified by the notion of animal consciousness. Historically, the science of psychology has been reacting for fifty years or more against earlier attempts to learn how we think by thinking about our thoughts. ...In other realms of scientific endeavor we have to accept proof that is less than a hundred percent rigorous... think of cosmology, think of geology. And Darwin couldn't prove the fact of biological evolution in a rigorous way. (Donald Griffin)