They are rigorously logical and fiercely independent in their thinking -- are indeed skeptical of all ideas, even their own -- and they believe they can overcome any obstacle with their will power.Often they are seen as cold and distant, but this is really the absorbed concentration they give to whatever problem they're working on.
Rationals might tackle problems in organic systems such as plants and animals, or in mechanical systems such as railroads and computers, or in social systems such as families and companies and governments.
But it must be said that any kind of strategic exercise tends to bring added strength to engineering as well as organizing skills.
Hardly more than two percent of the total population, Fieldmarshals are bound to lead others, and from an early age they can be observed taking command of groups.
David Keirsey expanded on the ancient study of temperament by Hippocrates and Plato.
In his works, Keirsey used the names suggested by Plato: Artisan (iconic), Guardian (pistic), Idealist (noetic), and Rational (dianoetic).