An engineered language is a constructed language created for the purpose of studying the inner mechanisms of language. One type of engineered language is a philosophical language, which is constructed to study the philosophy of language. The greatest of these is aUI, the "language of space." Invented by John Weilgart in the mid 20th century, aUI was designed to transcend communication across the universe. aUI is an oligosynthetic language of semantic primes, or universal elements that cannot be simplified any further. Its most distinguishing feature is that its orthography, phonology, and morphology are one and the same. If words look and sound the same, they mean the same. Of all the engineered languages, aUI is the best for studying the philosophy of language. No other language gets to the root of orthography, phonology, and morphology as well as aUI.