Both ideologies seem to have a dictatorship-like system of governance, no tolerance of dissenting opinions, and an executive which holds absolute power.
What is the difference between these two ideologies? Is one a subset or precondition of the other; that is to say, is it possible for a government to be totalitarian without being authoritarian, or vice-versa?
From a very abstract point of view, the difference is that totalitarianism desires to completely (totally) influence the thoughts and actions of its citizens, even into the private sphere, while authoritarianism is primarily concerned with keeping public life ‘in order’ and will allow for private affairs to remain private decisions.
Examples (albeit exaggerated) might show this better.
A totalitarian system such as state socialism/communism/whatever you want to call it as it was practiced in Eastern Europe intended to totally transform the citizens into communist supporters. The entire system relied on everybody following suit everywhere. Children selling leaves for pebbles would already be suspect to dangerous to this system where monetary gains and capitalism were to be eliminated. Thus, emphasis was based on the proper education (and if necessary re-education) to make sure the ideological background remained intact. The key thing that keeps the ruling dictators in power is the belief that this is the ‘best’ system.
Authoritarianism needs none of this control. In authoritarianism, the key thing that keeps the powerful in power is, well, power. Essentially, the powerful don’t care what you do as long as that specific thing you’re doing isn’t eroding their power. There is often (but not necessarily) no ideology behind the rulers, they were just there when opportunity arose. Thus, they don’t have an ideology that everybody needs to follow. People are often somewhat free to follow their own affairs and beliefs as long as the system as a whole is not questioned too strongly and no revolutionary cells are created. On the other hand, there is often a lot of emphasis on police, secret services and law enforcement to make sure that any rebellion is squashed before it occurs.
Of course, in real systems the distinction is not always clear cut, systems can move from either side of the foggy divide to the other and back. In fact, if you analyse the history of various states of the Communist Bloc you are most likely to find periods in which a state is more likely to be described as authoritarian and others where it is more likely to be described as totalitarian – these two might even apply to different states at the same time.
This answer purposely only takes past regimes as examples. Concerning the present, draw whichever parallels you want.
Authoritarianism is a general concept that points at a preference for a rigid, top-down hierarchical power structure. Authoritarianism demands obedience to orders and compliance with rules and laws, and calls for sharp use of both judicial and extra-judicial force to maintain that strict social order. Authoritarianism occurs — put prosaically — when some person or group demands fealty and obedience as a matter of (naked) power in its own right.
Totalitarianism is a form of authoritarianism in which this preference for rigid, top-down hierarchical power structures does not stop at merely enforcing obedience, but which extends into the personal lives of individuals to curtail any disagreement or disaffection with the state. Totalitarianism usually arises when an authoritarian state is combined with a dogmatic ideology of one sort or another: i.e., when power isn't merely power for its own sake, but is meant to force a particular worldview onto the populace to bring them into line with the state.
This distinction is fuzzy, of course, but there are litmus issues that distinguish a totalitarian state from a simpler authoritarian state. Totalitarian states tend to:
You might think of a totalitarian state as an authoritarian state that has adopted some of the operating tactics of malignant cults. Totalitarians don't merely want people to obey. Totalitarians want people to believe — to worship the state/leader and its ideals — and are willing to use terror, brainwashing, or whatever other psychological pressures they can apply to achieve that end.
Authoritarianism wants obedience, totalitarianism wants belief. As a consequence, authoritarianism tolerates an obediently behaving disbeliever, whereas totalitarianism persecutes and destroys them if it failed to destroy their disbelief first.
Authoritarian regimes always have ideology, even if as rudimentary as "public good". They always have a support base among the general public. Lose that support, and they fall (or become murderous dictatorships to prolong the regime's survival; the difference being in the percentage of regime-supporting vs. the oppressed-by-regime among the general public).
What they don't have, is a state-imposed belief system. That is the hallmark of totalitarianism.
Of course, those are two points on a spectrum. Or three, on a plane, if we add violent murderous naked-force dictatorship as another defining point.
This implies the existence of "soft" totalitarianism, and if you think it is impossible, consider societies which indoctrinate their children from birth. One example is the sci-fi movie THX1138.
In its society, people were indoctrinated so much they didn't even put up a fight (usually) against being caught by the police, or attempt to escape, and only argued whether they should be "utilized" or "destroyed", at their trial -- presumably, whether their remains were to be reused or discarded after their being put to death. The "utilized" verdict for one of the protagonists was considered a win, by the defense.
Totalitarianism is different from authoritarian in that it is specifically a type of authoritarianism where there is "[a] single power holder, usually an individual dictator". Totalitarianism usually gives absolute power to one individual or group with no alternative to remove the powers-that-be other than revolution. Totalitarianism also prevents common people from partaking in any form of decision-making. Meanwhile, authoritarian regimes like the USSR might allow for local elections that have some outcome based on votes from the people, limiting people's ability to partake in politics but still providing a limited say.
In the 1980s when Ronald Reagan was president, the U.S. was friendly with non-democratic countries like South Korea. Jeane Kirkpatrick (the ambassador to the U.N.) justified this by saying those countries were authoritarian, whereas the communist countries were totalitarian. (The counter-argument was that any dictatorship could simply call itself anti-communist and the U.S. would label them authoritarian and be friendly to them).
A bit more info here: https://en.wikipedia.org/wiki/Kirkpatrick_Doctrine
Totalitarianism was a term coined by the political theorist, Hannah Arendt, to describe two pathological forms of government, Nazi Germany and Stalins USSR. She described as a kind of state power that reached into the very mind and spirit of the citizenry.
Authority is a neccessary part of power. To enforce the law, for example. To make sure school curricula are worth studying rather than being a pile of junk and of course, to defend the nation. When it becomes excessive, it is called authoritarian.
One of the signal differences between totalitarianism and authoritarianism, according to Arendt, is it's relation to reality. Their propaganda system is generally a web of disinformation, onion like on its contours. This is famously and vividly brought to life in Orwells, 1984.
Herbert Marcise believed that a government could be totalitarian without being authoritarian. He identified totalitarian trends in Americam society in his 1964 book, One-Dimensional Man. He argued that:
Totalitarianism was not only a terroristic political coordination of society, but it was also the non-terroristic economic-technical coordination of society which operates by manipulation of needs by vested interests.
Norman Mailer, the novelist, also warned in the 60s that a new form of totalitarianism had slipped into the American psyche who, "trapped in the totalitarian tissues of American society" was fated to conform, despite the rhetoric of individuality.
This has been amplified by a book by Wolin, Inverted Totalitarianism where in the introduction he says:
Together the state and the corporation became the main sponsors and coordinators of the powers represented by science and technology. The result is an unprecedented combination of powers distinguished by their totalising tendencies, powers that not only challenge established boundaries - political, moral, intellectual, and economic - but whose very nature is to challenge those boundaries continually, even to challenge the limits of the earth itself. Those powers are also the means of inventing and disseminating a culture that taught consumers to welcome change and private pleasure while accepting political passivity. A major consequence is the construction of a new 'collective' identity, imperial rather than ... democratic.
It's worth recalling here, that during the Vietnam War, the philosopher Bertrand Russell, appalled at the atrocities committed by the USA forces in Vietnam, said there was nothing to differentiate what the USA did in Vietnam from the Nazi's - a genocide - and accused The New York Times of a coverup. In other words, the USA had gone through a period of fascism just as bad as the Nazi's.
It is a matter of (perhaps) fuzzy definitions, but Wikipedia claims that
[Totalitarianism] is regarded as the most extreme and complete form of authoritarianism.
The former term has been used with various shades of meaning though, e.g. it was
assigned a positive meaning in the writings of Giovanni Gentile, Italy's most prominent philosopher and leading theorist of fascism. He used the term totalitario to refer to the structure and goals of the new state, which were to provide the "total representation of the nation and total guidance of national goals". [...] According to Benito Mussolini, this system politicizes everything spiritual and human: "Everything within the state, nothing outside the state, nothing against the state"
Somewhat more controversially, the term has been used more recently used in "totalitarian democracy". I'm not incredibly familiar with this use, but it seems to be equivalent with an [extreme] "tyranny of the majority"; according to its proponents "totalitarian democracy"
retains full power of expropriation and full power of imposition, i.e., the right of control over everything and everyone. Maintenance of such power, in the absence of full support of the citizenry, requires the forceful suppression of any dissenting element except what the government purposely permits or organizes.
I guess no actual democracy reaches those levels, so "illiberal democracy" is a much more common term for a less extreme [but still] democratic regime.
In general though, most works use "totalitarianism" when they talk, usually in comparative manner, of Nazism and [Soviet] Communism/Socialism (as the latter was actually implemented).
I understand the difference, when expressed, has to do with the peoples a government seeks to exert domination over, its citizens (authoritarianism) or the outside world (totalitarianism.)
Rather than comparing theoretical definitions, let's look for the rare cases where recognizable experts distinguish between the two with factual regimes.
Wikipedia calls Franz Borkenau one of the pioneers in totalitarianism theory. In the 1950's he wrote a report for the U.S. State Department. The report began:
In the view of this writer a profound conflict between the Communist regimes of Russia and of China is in the long run as certain as anything predictable in politics. Its necessity can be demonstrated by a very simple formula. Totalitarian regimes live by an inherent urge to establish their absolute, “totalitarian” control as far as they can. A totalitarian regime, and more especially the Russian regime, is striving for absolute world domination. It therefore cannot have genuine allies, but must try to subjugate everything within its reach. This is incompatible with the obvious Chinese quest for national independence.
[Published in J. Tashjean, “The Sino-Soviet Split: Borkenau’s Predictive Analysis of 1952.” China Quarterly, No. 94 (1983)]
Six decades later, Joseph Sassoon, in Saddam Hussein’s Ba‘th Party: Inside an Authoritarian Regime (New York: Cambridge University Press, 2012), compares Hussein with Stalin, concluding that while many similarities exist, Saddam’s government was authoritarian, not totalitarian, since Stalin’s control over the military won wars, and Saddam’s did not. Sassoon's book has received unofficial recognition within the US intelligence community.
Based on these usages, it might be reasonable to associate totalitarianism with empire building, and assert the Roman Empire exhibited totalitarianism but less authoritarianism, because Roman citizens were (generally) treated with substantial deference both by their own government, and in any country in their realm of influence.
Totalitarianism may be thought as a unitary transformation that encompasses every sphere of the social, political and economic environments (the totality function), and this transformation process reproduces the conditions and elements of its totalitarian existence (unitary function) while it negates others. In a way, it is the underlying dynamics of the system (say, the differential equation determining the state of motion of the system as a whole). In these terms, we may agree the so-called real socialism of the XX century was essentially totalitarian.
The reproduction process of the totalitarian system may be constrained; for example, it may be directed, planned, controlled and/or regulated in an authoritarian manner or more or less democratically. In this sense, authoritarianism emerges as a constrain of the motion, not the fundamental forces that determine it. That's why dictators such as Hitler and Stalin, or Fidel Castro and Pinochet were the antithesis of each other.
