Blissymbolic is a non-spoken, pictographic, artificial language. It was invented by a psycholinguist named Charles Bliss as a truly international language, free of alphabets or other biases. It is comprised of a few thousand basic symbols which can be combined to form any needed word or phrase. The lack of an audible aspect makes it an ideal language for mentally disabled children, to segue into phonetic and eventually spoken language.
Bliss began to develop Blissymbols, which he called Semantography, in the 1940s, just as World War 2 was getting into gear. His main inspiration for formulating the language was his original difficulty in learning languages, due to their inherent illogic and self-contradictory rules. It certainly didn't help that his parents taught him mathematics and chemistry before he learned to read; to him, symbols were a logical expression of a logical set of rules. He originally developed Semantography as a solution to the massive language barriers in the scientific community, and then discovered its application in building language, logic, and pattern-matching skills in children and disabled persons.
Blissymbolic is designed to be learned intuitively rather than logically. To learn it, one can simply read the dictionary. The introduction of Blissymbols "classes" enraged Bliss, in fact; he claimed it "ruined his work and they ruined the logical sense of the children". His work in the area of universal semantics has gone almost entirely unacknowledged, save for in circles of caretakers of disabled children and some linguistic circles.