Chapter 5.                      Part D 

By contrast, Rationalism has other problems, especially with the Theory of Evolution.

For Plato, the whole idea of a canine genetic code that contained in it the instructions for the making of an ideal dog would have sounded appealing. It could have come from the “Good”. But Plato would have rejected the idea that back a few geological ages ago there were no dogs, while there were some other animals that looked like dogs, but were not imperfect copies of the dog "form". We know now that these creatures can be more fruitfully thought of as excellent examples of the species that they were supposed to be. All dogs, for Plato, should be seen as poor copies of the ideal dog which exists in the pure dimension of the Good. The fossil records in the rocks don’t so much cast doubt on Plato’s idealism as belie it altogether. Gradual, incremental change in all species? No. Plato, with his commitment to the “forms”, would have confidently rejected the Theory of Evolution. 

In the meantime, Descartes’ form of Rationalism would have had serious difficulties with the mentally challenged. Do they have minds/souls or not? If they don’t get Math and Geometry, or in other words, if they don’t know and can’t discuss most of the ideas that Descartes called “clear and distinct”, then are they even human? And, of course, the abilities of the mentally challenged range from slightly below normal to severely mentally handicapped. At what point on this continuum do we cross the threshold between human and animal? Between the realm of the soul and that of mere matter, in other words? Descartes' answers are revolting to us at the start of the twenty-first century. 

  

To Descartes, animals didn’t have souls, and therefore humans could do whatever they wished to them and not be violating any of his moral beliefs. In his own scientific work, he dissected dogs alive. Their screams weren’t, he claimed, evidence of real pain. They had no souls and, therefore, could not feel pain. The noise was like the ringing of an alarm clock, a mechanical sound, nothing more. Generations of scientists after him did similar acts in the name of Science. (2.) 

But I am digressing. For now, we can simply put aside our regrets about the Rationalists and the Empiricists, and the inadequacies of their ways of looking at the world. We are ready to get back to Bayesianism.   

Notes

1. http://www.math.cornell.edu/~mec/2008-2009/ TianyiZheng/Bayes.html 

        

          2. http://boingboing.net/2011/06/30/richard-dawkins-on-v.html