Well, there's at least somewhat of a biological basis for
   expressing one's feelings alongside one's thinking:* The
   amygdala ->prefrontal cortex circuit from the thalamus. It seems
   that the data stream (if one wants to use a computer-science
   analogy; it could easily be colored water in hoses) - goes from
   the thalamus and breaks up into two parallel streams, one for
   the prefrontal cortex and one for the amygdala. But the stream
   to the prefrontal cortex is slow and thin but the hose going to
   the amygdala is fat and fast; like a firehose. But then the
   amygdala feeds forward into the prefrontal cortex as well, with
   the force of a fireman's hose, influencing rational thought
   before rational thought even begins. that being said - the
   prefrontal cortex ALSO has a stream that feeds BACK into the
   amygdala, allowing one to utilize rational thought to inhibit or
   mitigate the power of the amygdala. But it's thin and slow and
   not a strong connection at first.* It can be built up through
   training (apparently), explaining the strength of many
   philosohpies/schools of thought/religions that have us "master
   our emotions". Yet, how much training does it take for your
   emotional to take over our rational thinking processes?* None,
   it seems! Emotion always influences reason [unless one has a
   damaged amygdala... ppl like that are in a perpetual state of
   reasoning... never able to commit to a decision because there's
   no emotional "push" to decide "true"/"false"/"best"/"worst"...
   must truly be a hell-on-earth.. .at least for those around them
   with functioning amygdalas]. So, in that sense, not that it's a
   requirement to pair up emotion and rational thought, it does
   make some biological sense.* At least, if one believes the whole
   circuitry notion of brain function anyhow.* We're still seeing
   what we want to see, after all, so that our scientific
   hypothesis and discoveries end up happening to match up to
   common patterns of existing human thought, it shouldn't be
   surprising. We've been primed to already :P