melancholicos esse_.[2] Shakespeare has very neatly expressed this
radical and innate diversity of temperament in those lines in _The
Merchant of Venice_:

[Footnote 1: Probl. xxx., ep. 1]

[Footnote 2: Tusc. i., 33.]

_Nature has framed strange fellows in her time;
Some that will evermore peep through their eyes,
And laugh, like parrots at a bag-piper;
And others of such vinegar aspect,
That they'll not show their teeth in way of smile,
Though Nestor swear the jest be laughable_.

This is the difference which Plato draws between [Greek: eukolos]
and [Greek: dyskolos]--the man of _easy_, and the man of _difficult_
disposition--in proof of which he refers to the varying degrees of
susceptibility which different people show to pleasurable and painful
impressions; so that one man will laugh at what makes another despair.
As a rule, the stronger the susceptibility to unpleasant impressions,
the weaker is the susceptibility to pleasant ones, and _vice versa_.
If it is equally possible for an event to turn out well or ill,
the [Greek: dyskolos] will be annoyed or grieved if the issue is
unfavorable, and will not rejoice, should it be happy. On the other
hand, the [Greek: eukolos] will neither worry nor fret over an
unfavorable issue, but rejoice if it turns out well. If the one is
successful in nine out of ten undertakings, he will not be pleased,
but rather annoyed that one has miscarried; whilst the other, if only
a single one succeeds, will manage to find consolation in the fact