The Tree of Knowledge

The authors of this book have a perspective that I find congenial, viz. a biological and evolutionary perspective. They employ it here to give an account of human understanding. Much of the book is taken up with tracing the evolution of organisms, with particular reference to the nervous system. They make the case that there is a continuous line of development from the simplest to the most complex of organisms, which retains the basic structure of the nervous system. "It couples the sensory and motor surfaces through a network of neurons whose pattern can be quite varied". (p159) a stimulus applied at the sensory surface causes a perturbation in the structure of the organism, which responds by making an adjustment which manifests as behaviour.

I refrain from making an extended précis as there are many summaries and commentaries online.

The human nervous system is highly complex, with the possibility of delayed (considered) and varied responses, over and above those of a more reflex nature. This elaborate realm of axons, dendrites and neurotransmitters is the field in which human faculties play: language, imagining, planning, thinking and so on. I.e conscious activities.

I follow M. and V. in their account of consciousness as biologically based. Some of their arguments against realism I find it hard to follow, the idea that we "bring forth a world" also the contention that consc. arises through language. These ideas I shall have to examine further, or else pursue others.

That last sentence reminds me that every writer on a subject has a different point of view, some overlapping, some widely divergent. And of course there are writers in a great many diverse fields. To acquire full knowledge of all domains of discourse would be impossible. Even a person who was widely read in one or a few fields would still be presented with alternative interpretations, singular viewpoints, and would be obliged to make a choice as to how much he would accept. And then how could he be sure he had acquired true knowledge?