| Thinking hard|
or hardly thinking?
|Major trains of thought|
|The good, the bad|
and the brain fart
|Come to think of it|
In philosophy and psychology, the tabula rasa (Latin for "erased writing tablet"[note 1]) or blank slate refers to a belief that humans are born without any innate mental content. Everything they know, and everything their minds and brains are able to do, is learned from perception and experience. It isn't true.
The phrase tabula rasa enters European philosophy with the translation of the works of Avicenna, but the idea of the mind as an "unwritten tablet" or "blank slate" goes back to Aristotle, who said it this way: "there is nothing in the intellect that was not first in the senses." It is particularly associated with the tradition of British empiricism, and specifically the thought of John Locke, whose Essay concerning human understanding begins with an extended argument favoring the idea. It was largely in this form that it was passed through and became a fundamental assumption of B. F. Skinner and the behaviorists.
- Parents of multiple children observe that their personalities appear to develop from certain varying and preset values that are reliable over their entire development.
- People must usually have some innate ability to acquire language; this faculty does not exist in other species and seems to be hereditary (though a minority of linguists, including Geoffrey Sampson, have vociferously argued against this)
- Most people know, even if they won't admit, that the minds of men and women appear to reliably differ from each other.
- Sexual orientation and sexual identity are by all reports involuntary, immutable, and fixed at birth. Reparative therapy reliably fails.
- Human social structures have identifiable analogues in the behavior of other primates and related mammals (a consequence of common descent in evolution).
- Humans seem to share a moral sense and a number of other inherent social concepts.
Challenges to this received idea came first from the field of linguistics. Noam Chomsky, reviewing Skinner's 1959 book Verbal Behavior, concluded that "The fact that all normal children acquire essentially comparable grammars of great complexity with remarkable rapidity suggests that human beings are somehow specially designed to do this, with data-handling or "hypothesis-formulating" ability of unknown character and complexity." Were the tabula rasa hypothesis true, it would be computationally impossible for human beings to acquire their native languages, much less acquire them with the speed and facility they do. Human children are able to speak well before they are able to handle other complex mental tasks. It therefore must be the case that normal human brains come equipped factory-standard with a facility for processing and using language. Other inborn human abilities can be easily demonstrated by the structure of the typical human body. No one had to teach you, nor did you have to figure out yourself, how to use the parallax of your two horizontally separated eyes for the purpose of depth perception, for example. Your brain came pre-equipped with a module to process binocular vision.
The cognitive revolution in psychology concluded that, just like the complex innate mental structure that must underlie language, that human minds have a number of properties that emerge from the structure of the brain. Unsurprisingly, we are built to process binocular vision and our motor cortex is kludged to allow us to walk bipedally. Jonathan Haidt has shown that human morality is preverbal and instinctual; and that it appears to be modular, modulated by specific moral dynamics such as "help versus harm" and "purity versus disgust." Twin studies have suggested both that personality traits such as shyness or sociability have a strong inherited factor, while the raising of unrelated children under the same roof does little to harmonize their temperaments or belief systems.
- Since paper and parchment were expensive luxuries, the Romans used boards covered with wax for jotting down notes. They would scrape away the topmost layer of the wax to erase it.
- See the Wikipedia article on Avicenna.
- Aristotle, De anima iii.4
- John Locke, An Essay Concerning Human Understanding, book I.
- Steven Pinker, Steven Pinker: Human nature and the blank slate (YouTube link), Feb. 2003)
- Noam Chomsky, A Review of B. F. Skinner's Verbal Behavior, rev. 1967.
- Gregory Casey, Human Genetics for the Social Sciences (Sage, 2000), ch. 22