ORIENTATION

Substances, as I have described them, are whatever one can learn from given only one or a few encounters, various skills or information that will apply on other encounters. Further, this possibility must be grounded in some kind of natural necessity. The function of a substance concept is to make possible this sort of learning and use of knowledge for a specific substance. For this, the cognizing organism must be able to recognize the specific substance under a variety of different conditions, as many as possible. It needs to do this, first, to grasp that the substance it is learning about over various encounters is one and the same so that knowledge of it can accumulate and, second, so that the accumulated knowledge can be applied. For substance concepts to be employed in the service of theoretical knowing – employed for knowing that rather than knowing how – the substance must be represented in thought in a univocal way, the same substance always represented as being the same. This makes possible a stable, unequivocal, and nonredundant inner representational system.

The ability to recognize what is objectively the same substance again as the same despite wide variations in the faces it shows to the senses is necessarily fallible. Although you surely have many ways of identifying each member of your immediate family – similarly for water and for cats – there will always be possible conditions under which you would misidentify them, mistaking them for someone or something else.