Greek stage.

Nor must we forget that Euripides is a greater admirer of nature, a more
complete delineator of her workings, than the two greater tragedians. He
has more of illustrative philosophy, more of regard to the objects of the
animated creation, the system of the universe, than his greater rivals
exhibit. He is, as Vitruvius has justly styled him, a "stage-philosopher."
Did we possess a larger acquaintance with the works of Parmenides,
Empedocles, and other early cosmogonists, we should perhaps think less of
his merits on this head: as it is, the possession of some such fragments of
our poet makes us deeply regret the loss of the plays themselves.

But his very love for the contemplation of nature has in no small degree
contributed to the mischievous skepticism promulgated by our poet. In early
times, when a rural theogony was the standard of belief, when each star had
its deity, each deity its undisputed, unquestioned prerogative and worship,
there was little inclination, less opportunity, for skepticism. Throughout
the poetry of Hesiod, we find this feeling ever predominant, a feeling
which Virgil and Tibullus well knew how to appreciate. Even Euripides
himself, perhaps taught by some dangerous lessons at home, has expressed
his belief that it is best "not to be too clever in matters regarding the
Gods."[2] A calm retreat in the wild, picturesque tracts of Macedonia,
might have had some share in reforming this spoiled pupil of the sophists.
But as we find that the too careful contemplation of nature degenerates
into superstition or rationalism in their various forms, so Euripides had
imbibed the taste for saying startling things,[3] rather than wise; for
reducing the principles of creation to materialism, the doctrines of right
and wrong to expediency, and immutable truths to a popular system of
question and answer. Like the generality of sophists, he took away a
received truth, and left nothing to supply its place; he reasoned falsehood
into probability, truth into nonentity.

At a period when the Prodico-Socratic style of disputing was in high
fashion, the popularity of Euripides must have been excessive. His familiar
appeals to the trifling matters of ordinary life, his characters all
philosophizing, from the prince to the dry-nurse, his excellent reasons for
doing right or wrong, as the case might be, must have been inestimably
delightful to the accommodating morals of the Athenians. The Court of
Charles t