An argument map or argument diagram is a visual representation of the structure of an argument. An argument map typically includes all the key components of the argument, traditionally called the conclusion and the premises, also called contention and reasons. Argument maps can also show co-premises, objections, counterarguments, rebuttals, and lemmas. There are different styles of argument map but they are often functionally equivalent and represent an argument's individual claims and the relationships between them.
Statements 2, 3, 4 are independent premises.
Statement 4 is an intermediate conclusion or sub-conclusion.
A diagram of the example from Beardsley's Practical Logic
A box and line diagram of Beardsley's example, produced using Harrell's procedure
Critical thinking is the analysis of available facts, evidence, observations, and arguments in order to form a judgement by the application of rational, skeptical, and unbiased analyses and evaluation. The application of critical thinking includes self-directed, self-disciplined, self-monitored, and self-corrective habits of the mind, thus a critical thinker is a person who practices the skills of critical thinking or has been trained and educated in its disciplines. Philosopher Richard W. Paul said that the mind of a critical thinker engages the person's intellectual abilities and personality traits. Critical thinking presupposes assent to rigorous standards of excellence and mindful command of their use in effective communication and problem solving, and a commitment to overcome egocentrism and sociocentrism.
In the West, critical reasoning originated from the teachings of the Greek philosopher Socrates (470–399 BC).