  The key difference then between the idea of God on the one hand and the idea of a necessarily existing lion is that the former can be clearly and distinctly perceived. For Descartes, it is just a brute fact that certain ideas can be clearly and distinctly perceived and others cannot. Some critics have charged him with dogmatism in this regard. Why should Descartes be allowed to legislate the scope of our clear and distinct perceptions? Perhaps we can clearly and distinctly perceive something that he could not.