The object was to make a language so powerfully expressive for logic and calculation that people learning it would think better if the hypothesis was true.
He intended it to be as culturally neutral as possible, logically and linguistically powerful, incorporating all known expressive features of any language (e.g. compounded location tenses), metaphysically parsimonious (e.g. you are not required to express any feature of reality, as you are in English time-tenses of verbs), and totally regular and unambiguous. He even used maximally stable phonemes.
The formal grammar was disambiguated mechanically (a first).
The language's grammar is based on predicate logic (the name is short for "logical language"), which also makes it particularly suitable for human-computer communication, an application that led Robert Heinlein to mention the language in his science fiction The Moon Is a Harsh Mistress.
Dr. Brown founded The Loglan Institute to develop the language and other applications of it. He always considered the language a research project that was never complete, so although he released many papers about its design he never "released" it freely to the general public. Because of this, a group of his followers later formed The Logical Language Group to create the language Lojban along the same principles, but with the intention to make it freely available and encourage its use as a real language.
The supporters of Lojban use the term Loglan as a generic term to refer to both their own language, and that of The Loglan Institute. They refer to the latter language as TLI Loglan when in need of disambiguation. Although the non-trademarkability of the term Loglan was eventually upheld in court, many supporters and members of The Loglan Institute find this usage offensive, and reserve Loglan for the TLI version of the language. In the rest of this article, Loglan will refer to both the language before the split, and TLI's version of the language after the split.
Loglan is very strange, because one can say things that are simply not meaningful. In natural languages, the ambiguity of the grammar hides these odd meanings.
For example, you can literally say that John, a person, is a short word. Or one can directly and precisely say any of the 22 different meanings of the English phrase "a pretty little girls school." This feature is so pronounced that people fluent in Loglan say impossible things as a sort of joke- a type of humour simply not supported by the linguistic machinery of other languages.
The oddest, most difficult thing for a speaker of an Indo-european language like English is that Loglan has no nouns or verbs, objects, direct objects, indirect objects, possessive forms or tenses. There are only predicates or functions, with places to place variables: e.g. botso: X buys Y from P for price Q. There are prefixes to reorder predicates, for example, price would be botso with a little word to make price the first variable. With different reorderings, one speaks of buyer, bought-thing, or seller. Tenses for time, location, actor, type of action, etc. are provided by "little words" which are optional. Predicates compound, so a predicate can fit in the variable of another predicate. Every language feature has standard, regular forms for acting in compounds. For example, time-travel tenses are possible trivially in Loglan (I did X from time Y to P in time Q.) using compounding forms normally used for location tenses.
After long use, the world has a sort of timeless, objectless, actorless flavor. Time words and location words fall away except when needed to make a point, usually with emotional emphasis. It is rather easy to avoid blame for responsibilities in loglan. Scheduling is ambiguous, you see, because the tenses are optional.
The language is designed so that the patterns of phonemes always parse into words. Thus, one cannot mumble Loglan, because even when run together, the language is still parsable.
See also: theory of language, artificial language, linguistics