Logorrhoea (US logorrhea) (Greek λογορροια, logorrhoia, "word-flux") is defined as an "excessive flow of words" and, when used medically, refers to incoherent talkativeness that occurs in certain kinds of mental illness, such as mania.

Logorrhoea is a language disorder present in a variety of psychiatric and neurological disorders including aphasia[1], localised cortical lesions in the thalamus[2][3], or most typically in schizophrenia with catatonia.

Examples of logorrhoea might include talking or mumbling monotonously either to others or more likely oneself. This may include the repetition of particular words of phrases, often incoherently. The causes for logorrhoea remain poorly understood, but appear to be localised to frontal lobe structures known to be associated with language. As is the case, for example, in emotional lability in a wide variety of neurological conditions, other symptoms take priority in clinical management and research efforts.

Logorrhoea should not be confused with pressure of speech, which is characterised by the 'flighty' alternation from topic to topic by tenuous links such as rhyming or punning[4]. Logorrhoea is a symptom of an underlying illness and should be treated by a medical professional. Several of the possible causes of logorrhoea respond well to medication.

The word logorrhoea is often used pejoratively to describe prose that is highly abstract and contains little concrete language. Since abstract writing is hard to visualize, it often seems as though it makes no sense and all the words are excessive. Writers in academic fields that concern themselves mostly with the abstract, such as philosophy and especially postmodernism, often fail to include extensive concrete examples of their ideas, and so a superficial examination of their work might lead one to believe that it is all nonsense.

The widespread expectation that scholarly works in these fields will look at first glance like nonsense is the source of humor that pokes fun at these fields by comparing actual nonsense with real academic writing. Several computer programs have been made that can generate texts resembling the styles of these fields but which are actually nonsensical. A physics professor even had such an essay published in a respected journal as a practical joke. See Sokal Affair.

Logorrhoea can also be used as a form of euphemism, to disguise unpleasant facts and ideas.

In his essay "Politics and the English Language" (1946), the English writer George Orwell wrote about logorrhoea in politics. He took the following verse (9:11) from the book of Ecclesiastes in the Bible:

I returned and saw under the sun, that the race is not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favour to men of skill; but time and chance happeneth to them all.

He rewrote it like this:

Objective considerations of contemporary phenomena compel the conclusion that success or failure in competitive activities exhibits no tendency to be commensurate with innate capacity, but that a considerable element of the unpredictable must invariably be taken into account.

Note Orwell's deliberate usage of unnecessary words that only serve to further complicate the statement. For instance, the words "objective" and "invariably" could be cut with virtually no loss of meaning. (Ironically, however, because the King James translation contains archaic grammar, some contemporary academics may find Orwell's version actually easier to understand.)

In his anecdote collection Surely You're Joking, Mr. Feynman!, the physicist and raconteur Richard Feynman describes a time when he participated in a multi-disciplinary conference discussing the nebulous topic "the ethics of equality". Feynman was at first apprehensive, having read none of the books the conference organizers had recommended. A sociologist brought a paper he had written beforehand to the committee where Feynman served, asking everyone to read it. Feynman found it completely incomprehensible and feared that he was out of his depth—until he decided to pick one sentence at random and parse it until he understood. The sentence he chose (to the best of his recollection) was

The individual member of the social community often receives his information via visual, symbolic channels.

Feynman "translated" the sentence and discovered it meant "People read". The rest of the paper soon made sense in the same fashion.

Further examples are easy to create:

Doctors say that the best way to lose weight is to eat less.

The medical community indicates that downsizing average total daily intake is maximally efficacious in the field of proactive weight-reduction methodologies.

He is the sort of person who will call a spade a spade.

This man is a member of the personality class exhibiting the tendency to term a pedally operated humus redistribution device a pedally operated humus redistribution device.

• Politics and the English Language by George Orwell.
• Fowler's Modern English Usage
• Grandiloquence
• Pleonasm
• Elegant variation
• SCIgen, a program that randomly generates a research paper for use as a hoax.

• The Postmodernism Generator -- A computer program that writes meaningless but highly convincing postmodern essays
• This Day in Paradigms -- Another automated postmodern essay generator
• The Sokal Affair -- More on the Sokal affair
• Scott Pakin's automatic complaint-letter generator
• A Markov text generator generates nonsense in the style of another work, because the probability of spitting out each word depends only on the n words before it