Composition – assuming that strong parts, when assembled, make a strong whole.
 

The fallacy of composition occurs when an author assumes that strong parts, when combined, make a stronger whole.  In many cases this is true: strong building materials will usually make the whole house stronger — assuming the construction crew did their jobs properly.  This fallacy usually overlooks important variables that affect the way that pieces join together to form complete sets.

A coin collection is usually more valuable if the collector has more individual coins of great value; however, if his collection contains millions of common pennies in terrible condition, then his collection is not worth what the collector thinks.  The error occurs when an author argues (from the true premise) that because individual parts contain certain property (onto the false conclusion) that the unified whole must retain the value of the same property.
 

EXAMPLE 1

A young NBA fan says: “The NBA All-Star team could whip the Lakers any day of the week – they’re all-stars for crying out loud!”

Although all-star teams do contain most of the best players in the league, to suggest that removing these players from their teams and throwing them together as an all-star team will automatically create a better team ignores key facts about how a team operates.   Some teams run different plays and have different skills.  If the all-star team consists of the best shooters, for example, we can assume that the team should score many points.  But what if they lack defensive skills, such as rebounding or blocking shots?  The teams that win the championships usually contain players who complement each other: different players master different roles.

To further assume that an all-star team will play as smoothly as a group of players who have played together for years is fallacious.  Often times, all-star games are simply showcases for individual talent, voted onto the team by their fans.  Championships are won by the best teams whose players know how to capitalize on their teammates’ tendencies and compensate for each other’s weaknesses.  A smoothly running machine does not roll off the assembly line.  The parts must prove that they can operate together before success can be achieved.
 

EXAMPLE 2

A smitten campaign supporter boasts: “Just imagine, if we had a governor like him in every state, what a great country this would be!”

The challenges of managing each state.  A governor may be effective and popular in one region of the country, but be misunderstood, ignored, or despised in another.  To assume that a governor will be equally effective when placed in a different climate is fallacious reasoning.

This governor, however, will emphatically argue that his skills as governor of one state qualify him to govern another state (or the nation, as our President).  The only measure of really proving this, however, is to elect this governor and then evaluate his performance four years later.

 
EXAMPLE 3

This student thinks he is clever: “I was just assigned a 20-page essay on the Civil War, but I have already written four 5-page essays in the past on this topic, and I received an ‘A’ on each one.  All I have to do is synthesize these four essays into one giant essay, and I’ll receive an easy ‘A.’”

Although it just might work, this student ignores the most important problem facing this type of synthesis: combining four essays that prove four different theses cannot be achieved by simply cutting and pasting these essays together.  If the 20-page essay needs to view the Civil War from the Confederate perspective, for example, then each of the previous four essays would need to have addressed this point of view in order to be valid.  The parts might have been superb, but the whole cannot survive on these parts alone.