Dynamics of Personality Type : Understanding and Applying Jung's Cognitive Processes (Understanding yourself and others series)
I think everyone has their own model of the universe made with an eye for leverage. But I think that is their Ti function. For a symbolic I_TJ, the Ti function would serve as either a source of discovery or a critical parent (so the theory goes). Their model of their universe would give them insights, and/ or admonish ill-concieved notions, goals or impressions.
While for a symbolic I_TP, Ti would serve a leading or dominating function. It would be in charge. Their leverage-aimed-model-of-the-universe determines their course of action, and sets goals (but healthy use requires it being informed by other functions, particularily the Auxiliary Se or Ne).
There are various other roles Ti could play (support/overprotection in E_TPs, Relief/Unsettling in I_FJs, aspirational/projective in E_FJs, backup/opposing in E_TJs, comedic/deceiving in E_FPs, Transformative/Devilish in I_FPs)
The same is true for all functions. Which way do you think you use Ti?
Are you sure you are not an INTP?