James Patrick at ShoutLife.com

INTPs are logical, individualistic, reserved, and very curious individuals.
They focus on ideas, theories and the explanation of how things work and have the ability to focus intently on a subject.
They are especially adept at discussions and debate and both appreciate and respect intelligence in others.

"INTPs are relatively easy-going and amenable to most anything until their principles are violated, about which they may become outspoken and inflexible.
They prefer to return, however, to a reserved albeit benign ambiance, not wishing to make spectacles of themselves."
- INTP Profile (TypeLogic)

"The INTP is above all a thinker and his inner (private) world is a place governed by a strong sense of logical structure.
Every experience is to be rigorously analysed, the task of the INTP's mind is to fit each encountered idea or experience into a larger structure defined by logic."
- An INTP Profile (intp.org)

"INTPs live in the world of theoretical possibilities. They see everything in terms of how it could be improved, or what it could be turned into.
They live primarily inside their own minds, having the ability to analyze difficult problems, identify patterns, and come up with logical explanations.
They seek clarity in everything, and are therefore driven to build knowledge. They are the "absent-minded professors", who highly value intelligence and the ability to apply logic to theories to find solutions."
- Portrait of an INTP (The Personality Page)

The INTP's "distant goal is always to rearrange the environment somehow, to shape, to construct, to devise, whether it be buildings, institutions, enterprises, or theories.
They look upon the world -- natural and civil -- as little more than raw material to be reshaped according to their design..."
- The Portrait of the Architect Rational (iNTp) (Keirsey)

"INTPs contribute a logical, system-building approach to their work.
They like being the architect of a plan, because of the scheming and thinking involved, far more than being the implementer of that plan. Implementation tends to be drudgery. They are content to sit back and think about what might work, given their view of the situation.
INTPs may ignore standard operating procedures. The hours that they spend are not what is important to them, but rather the completion of their thought process"
- INTP - The Wizard (Lifexplore)

"likes solitude, not revealing, unemotional, rule breaker, avoidant, familiar with the darkside, skeptical, acts without consulting others"
- Jung Type Descriptions (INTP) (similarminds.com)