I doubt that people who busy themselves with such things think any longer that the mind is a tabla rasa. And if a person is not convinced that it’s not, I recommend a good strong case of 
depression. I have had at least two major episodes of that; and in between, in a more regular and daily way, I have been diagnosed now by three psychiatrists as having dysthymia, a form of depression described as low-grade and chronic. Some consider it over a lifetime more debilitating even than major depression. People suffering from those—the great swings for example of bipolarity–probably have killed themselves, but we low grade types just go on and on as our teeth fall out.
One shouldn’t trust psychiatrists. They are legalized pill pushers is all. I had pretty much diagnosed myself before I saw one of them in any case. If out of some perversity, one wishes to acquire an official case of depression, it’s not at all hard to do. One has only to mention an inability to sleep or too much of it, fatigue that goes to the bone, a general lowering of affect, an unpleasant loss of libido, did I say “fatigue,” and some suicidal “ideation” of course is de rigueur. But the capper, the sure fire nail in the coffin, is a family history of the stuff.
This gets most directly to the inadequacy of the tabla rasa notion. One may not wish to believe in genetics, but sadly they appear operative. My family tree could be called the family tree of depressed monkeys. The whole lot on my father’s side seems to have suffered it, and I am positive too that it appears on my mother’s—given how she acted—but I can’t trace her line back very far. Melancholia mixed with rage—a volatile tonic, I should say.
Man, what tempers. But when one moves around every minute of every day feeling one is floating just slightly above a steady undertow of bone jarring fatigue, one can, under life’s very minor irritations, such as a window that won’t open, or a dog that barks too much, or any number of equally idle and pointless things, just snap as if that thing were the proverbial last straw. But oh, one runs into a great number of last straws. There are a lot of them. Those straws come to seem more like matches for the always primed and slightly hissing flame thrower of one’s rage. Just a flick of your Bic in the wrong spot and Kaboom!
I have my own theory of depression that I will not attempt to defend or justify on anything other than my capacity, as it were, of participant observer of depression’s squirmy stuff. At root, at the fatal bottom, way back in the brain stem, is the fight/flight or fear/anger response. If the flight/fight response gets stuck, as it were, in an oscillating and conflicting mode, anxiety, or a heightened state of observational awareness is produced. Evolutionarily speaking people prone to anxiety might have served a purpose, being that kind of person that the rest of the tribe could count on to stay awake all through the night while on guard.
Who knows, it makes sense to me, but perhaps I am trying to believe that at least at one time depression served a purpose. But probably I am just trying to find a deeper meaning or mythological depth to what is no more than really screwed up biochemistry. These biochemical processes, I want to call what Freud called the deepest levels of the unconscious, the primary processes.
