Plato "tripartite soul" predates Freud's three-part mind. It consists of the appetitive (id), spirited (superego), and rational (ego) parts. In The Republic, he claims the perfect government reflects the human soul, being made up of three parts:
Id (appetitive): The masses, merchants and laborers — They have a free market, always seek to satisfy their personal desires, and want as much freedom as possible.
Superego (and spirited): The Military — seeks to maintain order and the rule of law.
Ego (and rational): The government, which in Plato's ideal republic would be a group of philosopher-kings who aren't allowed to own any wealth — They command the other two groups and maintain balance between the masses' wish for freedom and the military's wish for order.
Clausewitz calls War itself a strange trinity, comprised of
Primordial violence, hatred, and enmity (Id)
The interplay of chance and probability, the exercise of intuitive genius (Ego)
An element of subordination to policy, and thus to reason (Superego)
The command of the Army of Northern Virginia, at least through Chancellorsville:
Ego: Robert E. Lee — overall commander, principled but basically realistic, provided balance between Jackson and Longstreet.
Id: Thomas J. "Stonewall" Jackson — imaginative, risk-taking, bold, passionate.
Superego: James Longstreet — highly principled, the voice of logic and reason.
The command of the Alamo during its infamous 13-day siege:
Ego: David Crockett — well-spoken, noble, larger-than-life, and admired by both men, provided a counterbalance between the two.
Id: Jim Bowie — hot-blooded, brash, impulsive, and an alcoholic, but otherwise a respectable leader.
Superego: William Travis — smart, rational, heroic, and educated; inexperienced, but gradually respected by his men over time.
Basketball teams are prone to this, as they are much smaller than teams of other sports, with five players on the court at a time and three central ones often taking the leadership role:
Superego: Josef Stalin — Like Spock, cold and calculating, noted for personal discipline (paranoid personal discipline, but discipline).
Ego: Franklin D. Roosevelt — Like Kirk, eternally mediating between the two, knowing full well the risks of falling in either direction (fall to Winston, start World War III against Joe. Fall to Joe, lose Eurasia).
On the other hand, the Axis Powers provide a fine example of a dysfunctional, even neurotic, relationship:
Ego (weakened): Fascist Italy — Provides the template for the Fascist form of government yet they are not as warmongering as Hitler or the Japanese, a little more rational with rejecting Hitler's genocidal methods and the Japanese ideal of Honour, but had a poor performance in the war, which forced them to ally with the Allies at the last minute.
The leaders in Paris1919 were also dysfunctional, but not as much:
Id: Georges Clemenceau — Ambitious, feisty, and more than a little bit vindictive. This last bit gave him an intense and personal desire to see Germany pay.
Superego: Woodrow Wilson — Emphatically moral to the point of being puritanical, as well as being very cold and logical (he was not only a college professor, but he was part of the movement that tried to make political science as much like a science as possible). He insisted that the world comply with his moral conception of order, and didn't think much of anyone who disagreed.
Arguably, Wilson and Clemenceau should be reversed. Clemenceau, who had been a crusading civil rights journalist and who a clear-eyed, rational view of the future threat posed by Germany, was the superego, whereas Wilson, who combined extreme racism (even for his time) with naive idealism was the id.
Ego: David Lloyd George — An easygoing, personable fellow trying to mediate between the two. He want to punish Germany but not take vengeance; was OK with the League but didn't think it was workable; he thought self-determination was nice-seeming but that concessions had to be made to power politics; and he was consistently frustrated both by Clemenceau's vengeful scheming and Wilson's sermons. Unlike most in his position, he was overshadowed; as he put it, he was sitting between Napoleon (Clemenceau) and Jesus Christ (Wilson), so no wonder the agreement was so dysfunctional.
It didn't help that Lloyd George was simultaneously playing the Ego to the British Empire delegation, most especially Billy Hughes (bombastic, vindictive Australian PM in bed with Clemenceau; Id) and Robert Borden (Canadian PM, logical, a stickler for protocol, and in an uneasy alliance with Wilson; superego). Within that, Borden himself was playing Ego to Wilson's Superego and the collective Id of the British Dominions (led by Hughes but also including New Zealand's William Massey and South Africa's Defence Minister Jan Smuts) over the issue of League of Nations Mandates (Australia and New Zealand wanted German Pacific colonies and South Africa wanted Namibia; meanwhile Wilson was skeptical of this, seeing it as a crass land grab not in keeping with the true meaning of the mandate; at the same time Borden was vaguely in agreement with Wilson but was convinced that it would be more efficient if Canada administered Britain's colonies in the Americas as territories or perhaps even provinces).
Id: The legislature — represents the will of the people.
Superego: The judiciary — Guilty or not guilty? The judiciary also has to judge if a law is constitutional
Ego: The executive — the primary decision maker, they have to balance ideals and strategic objectives with the situation at hand, and they have to fulfill the desires of the legislature while still being under the criticizing eyes of the judiciary
Superego: The Times They Are a-Changin — mostly serious, moralistic social commentary songs
Id: Another Side of Bob Dylan — more lighthearted, mostly personal songs about relationships
The three members of Rush: Neil Peart (Superego), Geddy Lee (Ego), and Alex Lifeson (Id). Geddy also displays some Id tendencies but is overall more of an Ego than Alex.
On of the most popular classical 3-piece line-ups is the piano trio, consisting of piano, violin and cello. In this you have a treble instrument (violin) and a bass instrument (cello), both of which can be highly expressive in their own right, and an instrument that can be a bit of both (the piano). So violin & cello = Id & Superego (either way round - depends on the piece and the composer), while piano = Ego.
Id: John C. Calhoun (South Carolina) was devoted to his state, and would only support positions that would benefit SC. He even went so far as to suggest that they secede during the Jackson administration because of an unpopular tariff. Calhoun was the leading Southern Senator of his time, and he represented their desire to maintain states' rights in order to maintain the slave-based economic system.
Superego: Daniel Webster (Massachusetts) thought that the main goal of Congress was to protect the Union and the power of the federal government. He viewed the federal government as naturally superior to the state governments, and that the latter must follow every law and decision of the former. Embodying the nation's North, Webster articulated the idea of the Union so well that they basically sound exactly like what Abraham Lincoln said during The American Civil War.
Ego: Henry Clay (Kentucky) saw it as his goal to compromise between all sides in the Senate and avoid excessive regionalism. He thought that extremism on both sides would lead to crisis's that could threaten the Union. Clay distrusted both the abolitionists who wanted the immediate end to slavery as well as the Southerners who openly talked about secession if they were not satisfied. Clay represented the West, the new future for the United States.
Perhaps significantly, the aforementioned Lincoln was a native Kentuckian who greatly admired Clay, but lived in free state Illinois and took much from Webster.
The 3 famous Bolshevik leaders (although they'd be a superego next to anyone else):
Id: Trotsky. Fiercely passionate and often leading the army into combat.
Ego: Lenin. Trying to secure stability within his own party and nation. Even resorted to banning factionalism.
Superego: Stalin. Operating behind the scenes while securing his own power, gaining influence and ruling through bureaucracy rather than charisma like Trotsky.
The three leading computer operating systems, at least until the advent of Google OS:
Id: Linux allows you to do basically what you want, but it can get messy.
Superego: Mac does a lot for you, but doesn't like you to step out of bounds.
Ego: Windows is somewhat convenient, but also pretty open.
The three Democratic Party presidential nominees in 2016:
Id: Bernie Sanders, passionate, appealing to people's idealism.
Ego: Jared Padalecki — The Heart (the most emotional and sensitive of the trio), The Pollyanna, emotional, affectionate, spiritual, understanding, philosophical, mix of extroverted and introverted, balances between emotions and intellect/logic/pragmatism