Jerry Fodor has argued that we never really learn new class-concepts; we only learn new vocabulary for class-concepts we already have. For example, if you show me ten things and identify some as "flarn" and the others as "non-flarn", I might learn that the class-concept "flarn" applies to everything that is a flat, green, rectangular or triangular shape. I already had the concept of FLAT+GREEN+(RECTANGULAR OR TRIANGULAR) in my inventory of concepts; I just learned your word for this concept. Fodor argues that all lexical concepts--all concepts that are normally denoted by a single word in English--are innate. On this view, even the concept CARBURETOR is an innate concept. (He further supports this view with arguments designed to show that giving definitions of such concepts--in terms of necessary and sufficient conditions--is not possible using other, simpler concepts.) Let's call this view "extreme nativism".
OK - That was background. Here's my thought (had while walking back from teaching Logic this morning):
The essential claim of extreme nativism is that our class-concepts (at least, the lexical ones) are not learned in a classical empiricist sense--that is, we don't acquire these concepts via experience. They have always been a part of our mental inventory. (Note: Nativists don't deny that experience plays a role in our 'learning' concepts--we may have a concept innately, but we don't 'learn' it, in a sense, until we meet something in our expereince to which we apply it).
Perhaps this claim could be modified or restated to make it seem more plausible. The categories into which we sort the objects of our experience are a subjective contribution that our minds make to our experience, not a contribution that the objective, given reality makes to our experience. (William James says something like this--we classify and categorize things according to 'essences' depending on how it suits our practical purposes at the time). So, categorization is native to our minds, not a part of the world. Perhaps we don't create the class-concepts until we need them; it is not like there is a fixed set of concepts (including CARBURETOR) that is a part of our natural endowment that come out to play when we first meet something the concept applies to. Rather, we have an innate capacity to creatively make up class concepts in accordance with our practical purposes.
In some ways the great mystery (to scientists & philosophers of science) is, where do our concepts come from? And also, where do our hypotheses come from? The scientific method explains how we test our hypotheses, but it does not explain how we come up with them. My suggestion is that the creation of explanatory hypotheses and the conception of class-concepts are essentially and non-reductively products of our innate mental structures and capacities. No input from the external world determines our concepts and hypotheses for us; it is a part of our internal processing mechanism.
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"He Himself is our Peace." (Eph 2)
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