forum for week of Nov 7: kinds of apriori beliefs

Kant posited that there are additional apriori beliefs, called synthetic apriori beliefs (such as the belief that effects have causes) that are necessary in advance of any evidence, in order to collect and make sense of evidence. Kant’s explanation for the truth of these beliefs is somewhat related to idealism in that these beliefs are necessarily true because we make them so, due to the structure of our mental processes. Although, as Quine argues, perhaps even these beliefs may change, we must nevertheless, maintain some central apriori beliefs in order to live and form any aposteriori beliefs.

To add to Kant’s list of apriori beliefs, I wonder whether our basic biological instincts, such as the sensation of needing to eat or sleep, would also satisfy Kant’s criteria for synthetic apriori beliefs, since we seem to be aware of our need to do these things in advance of our collecting evidence to verify this (though the evidence does follow shortly after fulfilling these needs by the sensations of fullness or reinvigoration). Additionally, such instinctual reactions are necessary in order for us to be able to collect evidence to form further beliefs since we would not be able to live without fulfilling these needs. Should instincts be classified as apriori beliefs, however, they would likely be, like Descartes’ “cogito ergo sum”, considered as apriori but not necessary since animals’ instincts to eat could have been false . Of course, in that case, we wouldn’t have evolved in the way we have and thus wouldn’t be here to speculate on this matter.

Apriori beliefs seem to be extremely limited in number and this may be due to a false distinction between beliefs that can be obtained in the absence of evidence since even apriori beliefs involve the presence of a world. There is, therefore, a limit to the beliefs we can reasonably say could be apriori, though I am unconvinced that even these beliefs are entirely so, instead i would call them "as apriori as possible". If all that existed was a floating brain, would it really be able to form beliefs about mathematics or cause and effect without any evidence of the existence of objects? I would be inclined to say no: evidence requires apriori beliefs and apriori beliefs require evidence. Which came first would seem to be something of a “chicken or egg” question.