I'm going to state my case in a rather simplistic, question-begging, manner: Someone who is genuinely sad, I want to say, knows why. They are, in their sadness, in touch with the loss or damage with which they are afflicted. That is part of what it means to be sad. Someone who is depressed, however, does not really know why. A troubled relationship may cause them to be depressed, but this cause will not be functioning for them as a reason. Depression is the mind's shutting itself down so as not to feel painful feelings or recognise unpalatable relational truths, with the result that what the sufferer notices is just the resultant loss of inner life, emptiness, demotivation, anhedonia, etc.
|Melancholia by Hans Sebald Beham|
The first thing to be said about it is that really knowing why one is currently depressed, like having insight into one's current delusions, is an impossibility. So it isn't really clear what it would even mean to talk of knowing the cause of one's current depression.
The second thing to be said about it is that self-knowledge is a conceptually different kettle of fish than knowledge of matters of independent fact. When I am sad, I said above, I necessarily know why. That might seem like an odd thing to say so long as we take the sadness and the knowledge to be two different things. (The risk then is that we would start to think of some 'intrapsychic mechanism' that would need to be operating well for me to be in what could only be thought of as a contingent state of affairs: to be in touch with my sadness.) But that is not what I mean. What I mean is that sadness is itself the form that the knowledge of loss takes. Her grief is her recognition of his death and of her loss. (It is what true knowledge amounts to here - knowledge which informs both speech and spontaneous action, rather than knowledge which only informs the spoken word. The true knower of loss dwells in their new world, and does not merely possess a knack for responding with appropriate phrases.)
Depression, however, is not an awareness of a feeling. It involves an anxious shut-down of personal being, a turning against the painful business of living. Because it is not a knowing it does not have an intentional object in anything like the same way that sadness or happiness does. A request for the answer to 'why are you happy' is the same as a request for an answer to 'about what are you happy'. But depression has no aboutness. This is not to say that depression does not involve a person having a lot of thoughts such as 'I will never work again', 'I am clearly inadequate at relationships'. It can involve a lot of thoughts, and these thoughts are clearly about, well, whatever they are about. But the state of depression is not itself a recognition, a knowing. If anything the anxious preoccupations are attempts to fill the mind to ward off the unbearable sadness or anger.
This brings me to the question of what it is to be 'in touch with one's feelings' and the whole issue of the unconscious. The popular temptation is clearly to give the distinction between conscious and unconscious an everyday epistemic gloss. But once again this has us miss what is really important about the distinction. The person who is not 'in touch with' his feelings is in an important sense not able to have them. It is not as if we have some other person who is feeling them, whilst the person who is not in touch does not. It is rather than they cannot let them grow, remain; they cannot allow them to bud forth in their intentionality; small fragments of meanings and sensations do not flower into emotional attitudes. And so instead the body remains rigid, defences against anxiety remain high, and seeds of feelings do not grow and flower into affective attitudes.
So, now we have the distinction between sadness and depression in place, now, I am claiming, we have a use to which a distinction between reasons and causes can be put. Depression only has causes: it is not itself a meaningful relation to the world. Sadness or joy, however, have reasons: joy is the form that a genuine recognition of wonder and good fortune takes. They are about something, whereas the only sense in which depression is 'about' something is a borrowed one - borrowed from what the person's anger or sadness would be about were they to be able to feel them.
If someone now asks me whether sadness does not have its causes as well as its reasons, or whether the two might not combine, I would have to reply that they have misunderstood my intent, which was not to deploy a tacit distinction already in place to make sense of the difference between depression and sadness, but rather to give a sense to such a distinction by reflecting on the difference between depression and sadness.