The poem's reasonable query is that the reader, or at least someone out there, 'please explain tears'. 'What', asks Reid's narrator, 'do we gain by it' ... 'a faculty that interferes / with seeing and speaking / and leaves [us] feeling weaker'? The question is a good one, as the poem's allusion to Darwin, and by extension, evolutionary theory and survival of the fittest, throws into question the evolutionary benefit (if any) of such a disabling, emotionally-triggered reflex.
Almost incredible, then, that Nick Laird's second collection, On Purpose, published last summer, provides a near perfect answer to Reid's poem in a short little piece titled 'The Perfect Host'. For it turns out that recent scientific research has uncovered the benefits of emotional tears by comparing them with basal tears (constant, moisturising 'tears' that lubricate the eye) and reflex tears (as in 'those that flow / because an onion is reduced to pieces / or smoke strays from the barbecue', as Laird puts it). And the results have shown that emotional tears contain a greater number of toxins and in particular, higher rates of manganese, which is 'thought responsible', as Laird's poem notes, 'for sadness'. In spite of crying and its physically and socially debilitating effects, then, emotional tears help to rid our body of certain toxins, and also explain why, after a good cry, people often feel much better...
because you must know by now
that it loves you, your body,
and wants you to stay.
Quite a cheery sort of conclusion, don'tcha think?