What are the ways in which emotion might enhance and/ or undermine reasoning?
I don't think anyone would have the least doubt that emotions do both. When you're on a 'high', things
come easily to you, and when you're low, thinking can become an intolerable chore. I suppose your
question is not about the mechanism involved, so this leaves us with two 'faculties' that occasionally
contend with each other for priority. It also leaves us with two camps of informed opinion, which are
probably both right, but have thus far failed to discover a common denominator.
Briefly, the first camp is entrenched in the belief that reason is the 'glory of mankind' and should
therefore have priority; in particular, the advocates of this view contend that our emotional life is pretty
much the same as for all mammals, at a pinch more subtly responsive, but still pretty crude. A very
vocal proponent was the late Arthur Koestler, in his day a bestselling writer on interesting
philosophical issues (and therefore sometimes referred to as a philosopher, but that's probably
stretching it). At any rate, in his book The Ghost in the Machinehe gives an extensive analysis of the
troubles which our emotions cause us, who must live and work in societies which exceed in the
complexity of their organisation anything encountered elsewhere in the animate realm. In order to
give reason a chance, he proposes that conflict situations might be controlled by the administration of
some otherwise 'harmless' chemical substances. I suggest that this book, even though it might seem
dated, is eminently worth reading and not difficult to follow — after all, it was written with the general
public in mind and the issue itself can hardly be said to have made much progress since. I do not
suggest that Koestler was ever alone; rather he reflects a very widespread sentiment that emotions
can be and usually are the downfall of reason, although he also concedes their value. But altogether
he promulgates the notion that we human possess a kind of aggregate of emotional modules, what
he calls the inheritance from the croc, the horse and our hominid ancestors, all afflicted with an innate
'wiring defect'. This defect occurred because evolution cannot not dismantle structures once they're in
place, but only add to them; and since no designer was around to supervise the wiring, it happened
higgledy-piggledy, one on top of the other without any definitive resolution to the hierarchy in charge
of dealing with conflicts between emotion and reason.
NB: Another good book on the same subject is The Dragons of Edenby Carl Sagan. I'm deliberately
referring you to such semi-popular accounts, for unless you want to get embroiled in neurophysiology,
this is where all the relevant information is laid out.
Needless to add, that philosophers on the whole sound the same regretful note about the presumed
enmity between emotions and reason. Two notable exceptions are Hume and Schopenhauer; to the
first we owe the famous quote, 'reason is the slave of the passions'. But neither one of this pair is
really 'on the side' of the emotions. For this you have to go somewhere else.
You would obviously be aware that a lot of potboilers have been written recently with a view to
encouraging us to 'let it all hang out', as if there were some especial merit to emoting all over the
place. There is neither philosophical nor even any social merit in this and I suppose Koestler would
turn in his grave if he knew. Nevertheless, there are serious studies of the virtuesof the emotions;
and in particular of the indispensability of the 'despised' passions for the health of our reason. For it
must be said that, as much as emotions can be analysed down to positively harmful features of our
psyche, so reason, when examined closely, turns out to be a very fragile instrument, whose gravest
demerit is a kind of 'abstractedness' from life in the raw — in other words, it encourages in us a sort of
pristine dedication to truth, love, beauty etc etc which not infrequently gives one the impression of
having derived from cloud cuckoo land rather than any place you might find on earth. By the same
token, reason which leaves emotion behind is inhuman, and there is plenty of historical evidence to
prove this. Emotions and reason, in an ideal case, would keep each other in balance; and one way of
looking at this would be to take note of the value structureswhich we human have erected, which
might be said to reflect the good sides of both our emotional and rational faculties.
One book I have already recommended elsewhere in this issue can bear a second push; it is really an
outstanding contribution to what we should know about reason and emotion and how our mental
health depends on both of them. The book is Antonio Damasio's The Feeling of What Happens.
Damasio was (is) a practising psychiatrist and neurologist, and I dare say, what he doesn't know isn't
worth knowing. On top he is an exceptionally clear writer, so that I shall leave you in his capable
hands it you should feel like pursuing this matter further.