The threefold of experiencing, feeling, will and understanding (or thinking) are a Peircean, first, second and third, trichotomy - corresponding to spontaneous, oppositional and mediating. Feeling here refers to immediate sensations and presencings, or roughly what falls under qualia in its original sense when it hasn't been expanded phenomenologically to embrace all of experiencing. Most meditational practices such as breath counting and interior body observation emphasise feeling and willing, as if to correct the ordinary hegemony of thinking. (Willing is the persistence required to keep going.) For Peirce thinking is a process directed at the resolution of perplexity and so would correspond to meditation as inquiry. Thinking in the invidious sense, while still a mediational process and so a genuine thirdness, is passive and circular, neither of which is useless per se.