Keirsey Temperament Theory – an outline of the author's definitive book by Paul D. Gurney
(visit the author's website; author's copyright and ownership honored fully.)

Human beings come in 4 basic patterns. This has been recognized for at least 2,000 years. e.g. in 450 b.c. Hippocrates described four dispostions: choleric, phlegmatic, melancholic and sanguine.

Learn about the 4 underlying forms of personality, as evidenced by how people use tools and words, or what we say and what we do.

To Use the Matrix: First, determine how you use words: concrete or abstract; then how you use "tools": cooperative or utilitarian. The square you're in will give you a general idea of your Temperament. The types within are explained below under "Characteristics..."

You could also take the Sorter assessment.

NF
Idealists
Intelligence: Diplomatic
Interests: humanities, moral, personnel
the personal growth temperament
enthusiastic, romantic, soulful, ethical, intuitive

The Idealist's core needs are for the meaning and significance that come from having a sense of purpose and working toward some greater good. Idealists need to have a sense of unique identity. They value unity, self-actualization, and authenticity. Idealists prefer cooperative interactions with a focus on ethics and morality. Idealists tend to be gifted at unifying diverse peoples and helping individuals realize their potential. They build bridges between people through empathy and clarification of deeper issues.

iNtuitive and Fervent

SJ
Guardians
Intelligence: Logistical
Interests: commerce, morality, materiel
the cornerstone temperament
helpful, responsible, traditional, law-abiding, steady

The Guardian's core needs are for group membership and responsibility. Guardians need to know they are doing the responsible thing. They value stability, security and a sense of community. They trust hierarchy and authority and may be surprised when others go against these social structures. Guardians know how things have always been done, and so they anticipate where things can go wrong. They have a knack for attending to rules, procedures, and protocol.

Sensible and Judicious

NT
Rationals
Intelligence: Strategic
Interests: sciences, technology, systems
the technology temperament
theoretical, ingenious, logical, analytical, curious

The Rational's core needs are for mastery of concepts, knowledge, and competence. Rationals want to understand the operating principles of the universe and to learn or even develop theories for everything. They value expertise, logical consistency, concepts and ideas, and seek progress. They abstractly analyze a situation and consider previously un-thought-of possibilities. Research, analysis, searching for patterns, and developing hypotheses are quite likely to be their natural modus operandi.

iNgenious and Theoretical

SP
Artisans
Intelligence: Tactical
Interests: artcraft, techniques, equipment
the action temperament
daring, impulsive, spontaneous, playful, generous

The Artisan's core needs are to have the freedom to act without hindrance and to see a marked result from action. Artisans highly value aesthetics, whether in nature or art. Their energies are focused on skillful performance, variety, and stimulation. Artisans tend to be gifted at employing the available means to accomplish an end. Their creativity is revealed by the variety of solutions they come up with. They are talented at using tools, whether the tool be language, theories, a paint brush, or a computer.

Spontaneous and Playful

Marriage
Opposites attract, as the axiom goes. But there are many types of opposites. In temperament theory, two people could be opposites in 4 ways, and even all four letters could be different: e.g. an ESFP with an INTJ. Indeed, eight Personality types are completely the "opposite" of the other eight.

So which opposites enrich the relationship (your weakness is my strength) and which erode the bond?

Keirsey wrote that Rationals should marry Idealists, and Guardians should marry Artisans. He believed that concrete thinkers should partner up with concrete thinkers, and abstract thinkers with other abstract thinkers. The rationale seems to be because harmony in a relationship depends on effective communication; if we're not even speaking the same "language", we face a fundamental obstacle. Therefore, the only "opposite" that really threatened long-term viability was one partner being an abstract N thinker and the other a concrete S thinker.

The (E/I), (T/F) AND (P/J) pairings mattered much less, since these sorts of "opposites" could create the "your strength, my weakness" effect which leads to intrapersonal growth.

My personal belief is in line with his, with these questions: Do more pairings in common lead to greater harmony? Or are minor opposites always better for growth? i.e. Two Js can happily adhere to their scheduled routines (who will yield if they don't have the same priorities?). Two Ps can explore possibilities and generate exciting ideas (but will any major course of action get finalized?). Two Es can be the life the of the social group (or will they compete for attention and space?). Two Is can appreciate each other's halo of tranquility (but would they readily make new friends after a move to a new city?). Two Ts can smartly make difficult choices about their aging parents (but will other family members have their feelings ignored?). Two Fs can volunteer their free time helping all of the neighbors (but who will say "No" when personal time needs to be preserved?).

Interesting!

Keirsey does not make temperament and astrological connections, because astrology "types" are not scientifically valid – but the similarities are interesting!

More interesting patterns: Hippocrates humours; ancient Greek music modes...