Beyond the age of Abraham's call and the Septuagint count of Jacob's household, seventy-five carries no developed symbolism. Modern numerology reduces it to three and reads it through that root as a number of expression and growth. The number's honest content is the two scriptural figures, one fixing the start of the Abrahamic covenant and one preserving a textual difference between the Hebrew and the Greek Bible.
Florence Campbell, a student of Balliett's, restated and extended the chart in Your Days Are Numbered in 1931, and Juno Jordan, founder of the California Institute of Numerical Research, standardised the modern four-part chart of life path, expression, soul urge and personality numbers in 1965; both writers worked from name and birth date rather than from any older number philosophy.
The genuine Pythagorean number philosophy that this modern chart borrows its name from left no writings of its own: Pythagoras and his early followers taught only by mouth, and what survives of their number theory comes instead through Nicomachus of Gerasa, whose Introduction to Arithmetic of the first century CE became the standard authority for a thousand years, and through Iamblichus, who drew on Nicomachus two centuries later; neither wrote anything resembling a name-and-birthdate numerology.