"Heretic" only means "one who chooses," and "heresy" means simply "a choice." (Greek, hairesis, choice.) A "heretic" is one who chooses his own creed, and does not adopt the creed authorised by the Roman Catholic Church.

"HERETICS" OF THE FIRST CENTURY were the Simonians (so called from Simon Magus), Cerinthians (Cerinthus), Ebionites (Ebion), and Nicolaitans (Nicholas, deacon of Antioch).

"HERETICS" OF THE SECOND CENTURY were The Basilidians (Basilides), Carpocratians (Carpocrates), Valentinians (Valentinus), Gnostics (Knowing Ones), Nazarenes, Millenarians, Cainites (Cain), Sethians (Seth), Quartodecimans (who kept Easter on the fourteenth day of the first month), Cerdonians (Cerdon), Marcionites (Marcion), Montanists (Montanus), Tatianists (Tatian) (The Tatian of the second century was a Platonic philosopher who wrote Discourses in good Greek; Tatian the heretic lived in the third or fourth century, and wrote very bad Greek. The two men were widely different in every respect), Alogians (who denied the "Word"), Artotyrites, and Angelics (who worshipped angels).