Theories aren't Always Intellectual Constructs

  
You seem to have a problem with the word "theory" (that is, Quine's usage of that term). Perhaps if you didn't take the term so intellectually or scientifically.

 
Take a term outside Quine's usage.


Virtually all philosophers of mind use the term "folk psychology". And virtually all these philosophers deem folk psychology to be "theoretical" or a "theory". Folk psychology is a theory upheld by the folk, or the Man on the Street; though that doesn't thereby mean that every member of the folk sat in his or her armchair and devised a theory of mind or even of his own psychology.


Here's Paul M. Churchland on the matter:


"Not only is folk psychology a theory, it is so obviously a theory…The structural features of folk psychology parallel perfectly those of mathematical physics; the only difference lies in the respective domain of abstract entities they exploit - numbers in the case of physics, and propositions in the case of psychology." (From "Eliminative Materialism and the Propositional Attitudes", 1981.)


The theory philosophers call "folk psychology" is more or less inherited. Indeed Churchland thinks that the theory goes back to the ancient Greeks and hasn't really changed much since then. Though it is still, despite its long lineage, a theory. However, it's not an intellectual construct as such; at least not in terms of each individual who adheres (non-cognitively) to it. What it is, despite that, is a scheme of interrelated and mutually supportive concepts, beliefs, truths, etc.


There are numerous such schemes or theories held by many of us without much theoretical, scientific or philosophical hard work on our own part. For example, an individual could accept a huge theory (say, an ideology, religion or philosophical system) without doing much cognitive hard work. The point is, however, that he accepts the theory or is simply born into it. A theory, theoretically, could include only, say, three interlinked and mutually supportive concepts and/or beliefs, etc. And even then they may be accepted as a package-deal and not be knitted together by each individual who accepts them.


Quine's use of the term "posit" (in your example) may put people off a little. But according to Christian theory in the Middle Ages, demons, angels, etc. were posited. According to scientific theory in a previous century phlogiston was posited. According to Aristotelian metaphysics the earth as being the centre of the universe was posited. And today "super strings", numerous particles of various description etc. may simply be posits.


As Quine said in one of your quotes, we can't ever be theory-less. We move around within conceptual schemes (large systems of inter-related theories). We can't achieve a view from Nowhere. Sometimes we may think or feel that we are theory-less (at least in certain respects) simply because we were born into particular theories or conceptual schemes. They now seem almost innate. But they are contingent. (However, certain ways of seeing the world may well be a priori. Say, for example, if one accepts a Kantian position on experience.)