Alcimus of Sicily (Ἄλκιμος ὁ Σικελιώτης) was a Greek historian active in the 4th century BCE. Beyond his Sicilian origin and period, no specific biographical details survive [1][2][3]. His work is known only through later citations, primarily by Diogenes Laertius.

His sole known work is a lost historical treatise, cited by Diogenes Laertius concerning Plato [1][2]. Its fragments indicate it contained biographical material on philosophers, arguing for a strong Sicilian, particularly Pythagorean, influence on Plato’s philosophy. One fragment claims Plato borrowed many ideas from the Pythagorean Epicharmus of Syracuse [2][3].

Alcimus is a minor but notable figure in early Hellenistic historiography. His work represents a strand of biographical writing that traced philosophical lineages, and his argument for Pythagorean influence on Plato is an early example of intellectual historiography connecting Athenian philosophy with Italic and Sicilian traditions [1][2]. The fragments provide a window into 4th-century debates on Platonic thought.

Sources 1. Stanford Encyclopedia of Philosophy (Plato): https://plato.stanford.edu/entries/plato/ 2. Perseus Digital Library (Diogenes Laertius, Lives of Eminent Philosophers, Book III): http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.01.0258:book=3:chapter=1 3. Smith's Dictionary of Greek and Roman Biography and Mythology (via Perseus): http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0104:entry=alcimus-bio-1