Psychologists sometimes like to state - when in idol-smashing moods - that, despite an alleged bit of conventional 'wisdom', some allegedly discrete psychopathological phenomenon is actually on a continuum with non-psychopathological versions of the same. Thus delusions, for example, might be said to be on a continuum with normal, through eccentric, beliefs.
Now I don't want to take issue with this directly. But this is because the claim seems to me to be almost entirely empty. What it needs is some fairly radical further specification - of just what the continua or discontinua are to be. And beyond that, it needs to be conclusively demonstrated that the continuum dimension is the one which was driving the original formulation of the phenomenon.
So it would, I take it, be fairly hopeless to say something like: "Delusions tend to be beliefs that are just that bit more false, tend to be a bit more unshakeable, tend to be a bit more unshared... than normal beliefs. They can therefore be understood on a continuum with normal beliefs." Because all of that might be entirely true, but touch not at all on the idea lying behind any original discontinuity thesis.
Similarly with the allegedly Jasperian idea that delusions are "un-understandable". Of course there will be all sorts of ways in which delusions are understandable, or nearly, say, as understandable as other eccentric and normal beliefs. But so what? Are we certain that the kind of un-understandability that Jaspers was after was a kind which would accrue in all contexts - be they the rational relations of the belief to other beliefs of the subject; the belief's psychodynamic / motivational character; existential aspects, etc? Jaspers seemed fairly clear, after all, that the kind of ununderstandability he was after was one of our not, as it were, being able to 'make the belief our own' - to feel our way into it from the inside - despite any amount of external or intellectual grasp we may arrive at through the deployment of whatever hermeneutic device at our theoretical disposal.
So I'd like to propose that psychologists be encouraged to just stop offering a combination of blankly empirical or 'external' (as Jaspers would have put it) criteria for some psychopathological phenomenon, and then, after having found that simply by deploying such criteria we get a nice continuum from the pathological to the normal, coming out with the claim that 'after all, the pathological phenomenon is not so pathological as we might have thought'. Maybe that final point is a good claim, maybe it isn't; whether it is or not will depend on whether the continua dimensions really do capture the essential character of the phenomenon as originally intuited by the psychopathologists.
A meta-psychological and historical comment: Variations of the above-described theoretical tendency are notable in other psychological contexts too. I remember as an undergraduate being asked to believe that Piaget's developmental stages (pre-operational, concrete and formal operational etc.) could be shown to have occurred somewhat earlier than the great man suggested. The moral seemed to be that careful, scientific, empirically guided research can reveal that more intuitive, theoretical, philosophical approaches can underestimate the capacities of the child (or underestimate our ability to understand what the person who is deluded is saying). But, needless to say, along the way some quite blandly empirical criteria which were not at all Piaget's had been substituted for his own (admittedly more theoretically complex ones), and the 'striking finding' that the great thinker had underestimated the capacities of children was largely an artefact of this criterial substitution. (The story of the developmental psychologists' misreading of Piaget's genetic epistemology is documented in Chapman's book Constructive Evolution: Origins and Development of Piaget's Thought.)
This sets me thinking about the relation between empiricist and (let's call them) ontological approaches in psychology. As the now-cliched adage from Kant has it, "thoughts without [experientially specifiable] content are empty; intuitions [i.e. sensory experiences] without concepts are blind". If I lived in France then no doubt I'd find myself railing against the theory-mongerers for their lack of attention to the empirical grounding or - a better word owed to Joseph Margolis - 'adequation' (i.e. specification as to what counts for or against a claim) of their theories. As it is, I live in England, and I find myself railing against the theoretical impoverishment of the 'intuitions without concepts' I encounter.