**Deskilling**

*Astro Teller, head of the X division, has on several occasions said that the company’s tests show humans to be a poor fallback, because once they learn to trust self-driving technology they ignore the road and therefore are not well equipped to take over in the event of an emergency.*

- - Conor Dougherty, California D.M.V. Stops Short of Fully Embracing Driverless Cars, Dec. 16, 2015

*If anyone doubts the utility of symbols, let him write out in full, without any symbol whatever, the whole meaning of the following equations which represent some of the fundamental laws of algebra:-*

*x+y=y+x (1)*

*(x+y)+z=x+(y+z) (2)*

*...*

*For example, without symbols, (1) becomes: If a second number be added to any given number the result is the same as if the first given number had been added to the second number.*

*This example shows that, by the aid of symbolism, we can make transitions in reasoning almost mechanically by the eye, which otherwise would call into play the higher faculties of the brain.*

*It is a profoundly erroneous truism, repeated by all copy-books and by eminent people when they are making speeches, that we should cultivate the habit of thinking of what we are doing. The precise opposite is the case. Civilization advances by extending the number of important operations which we can perform without thinking about them.*

- - Alfred North Whitehead, An Introduction to Mathematics, p. 61