The results of ethnic psychology constitute, at the same time, our chief source of information regarding the general psychology of the complex mental processes. Wilhelm Wundt
A successful attempt to express logical propositions by symbols, the laws of whose combinations should be founded upon the laws of the mental processes which they represent, would, so far, be a step towards a philosophical language. George Boole
It is no exaggeration to state that the classic culture of Tlön comprises only one discipline: psychology. All others are subordinated to it. I have said that the men of this planet conceive the universe as a series of mental processes which do not develop in space but successively in time. Jorge Luis Borges
LSD is a catalyst or amplifier of mental processes. If properly used it could become something like the microscope or telescope of psychiatry. Stanislav Grof
Words for mental processes are all derived from physical things. Robert Smithson
Imagery is not past but present. It rests with what we call our mental processes to place these images in a temporal order. George Herbert Mead