Insidious realism: some backtracking

Looking back over what I have said about it, it seems that I have not yet nailed down what I call insidious realism. So let me say a bit more. Often when philosophers try to get clear about something, they assume, tacitly or otherwise, that the something in question is there, complete in itself, waiting to be properly explored and subsequently described. But in the interesting cases, this is rarely true  - if it were, philosophy would be much easier or redundant (think about it).
How often do we find philosophers discussing something like, say, desire as if the term "desire" designates something independent and complete in itself that accounts of it can either match or fail to match? Moreover, when a philosopher evinces some views about desire that are later worked up into a conception of desire by other philosophers working from an historical perspective, then the same assumptions about that conception often come into play. This generates two thick layers of fog.
In the latter cases, it is usually best to try to untangle what is there, so to speak, from what can be added, where the constraints on the additive process involve considerations such as consistency, utility, elegance and economy. Some times a degree of charity concerning one or more of these should come into play.