Again a treatise by Plutarch online at LacusCurtius: this time, the Sage of Chaeronea tackles superstition, trying to prove that it is worse than atheism. The full Greek text of his sermon is here; the English translation is here. I think it is the treatise with the most quotations from older sources in classical Greek literature.
Also available: brief items on the Judicati Actio (from Smith’s Dictionary) and the Boeotian town Abae.