Also, look at this definition of the Ti subtype:
Extractor is a self-profound and thoughtful person. He is attracted to ideas what have nothing to do with the reality, for example philosophy, religion, bio-energetics etc. His favourite occupation is to compare different systems of logic - he’s a typical armchair scientist. He may be awkward, he does not pay attention to his appearance, and doesn’t care about health.
Although it is definately concerning that this has a little bit of a contradictory view of the Ti subtype:
Logical subtype tries to produce the impression of serious person. It can be sharp, at times even unceremonious. It is confident in itself, he says rapidly, usually in categorical tone. It is superfluously categorical in its judgments, it has a tendency to tie by others its opinion. It sometimes seems energetic and self-confident. It is impatient and always it cannot listen collocutor to the end. He frequently is fascinated by something new, attempts to find to it practical embodiment. It actively and energetically defends its interests. In this case it can flare up and offend man, but, after noting this, he tries to correct position. It is very proud and it can be insulted because of the trifle, talk roughnesses, and it will be again affable and benevolent after a certain time. It is not predicted and contrasting in its behavior. View - first scattered, then testing, tenacious. The gait and the gestures sweeping, confident, but are badly coordinated. Poses free, flattened. It easily draws together distance, it can embrace, kiss collocutor.
Take of it what you will, but it seems to me that the first one is more cleanly articulated.