 “Neopythagorean” is a modern label, which overlaps with two other modern labels, “Middle Platonist” and “Neoplatonist,” so that a given figure will be called a Neoplatonist or Middle Platonist by some scholars and a Neopythagorean by others. There are several different strands in Neopythagoreanism. One strand focuses on Pythagoras as a master metaphysician. In this guise he is presented as the author of a theory of principles, which went even beyond the principles of Plato’s later metaphysics, the one and the indefinite dyad, and which shows similarities to the Neoplatonic system of Plotinus. The first Neopythagorean in this sense is Eudorus of Alexandria, who was active in the middle and later part of the first century BCE. He evidently presented his own innovations as the work of the Pythagoreans (Dillon 1977, 119). According to Eudorus, the Pythagoreans posited a single supreme principle, known as the one and the supreme god, which is the cause of all things. Below this first principle are a second one, which is also called the monad, and the indefinite dyad. These latter two are Plato’s principles in the unwritten doctrines, but Eudorus says they are properly speaking elements rather than principles (Simplicius, in Phys., CAG IX 181. 10–30). The system of principles described by Eudorus also appears in the pseudo-Pythagorean writings (e.g., pseudo-Archytas, On Principles; Thesleff 1965, 19) and it is hard to be certain in which direction the influence went (Dillon 1977, 120–121). On Eudorus’ connection to the pseudo-Pythagorean writings see also Bonazzi 2013 and Centrone 2014. A generation after Eudorus, another Alexandrian, the Jewish thinker Philo, used a Pythagorean theory of principles, which is similar to that found in Eudorus, and Pythagorean number symbolism in order to give a philosophical interpretation of the Old Testament (Kahn 2001, 99–104; Dillon 1977, 139–183). Philo’s goal was to show that Moses was the first philosopher. For Philo Pythagoras and his travels to the east evidently played a crucial role in the transmission of philosophy to the Greeks (Dillon 2014). Philo like Eudorus has close connections to the Pythagorean pseudepigrapha (Centrone 2014). 