Astrophysicist Stephen Hawking is an expert on many esoteric scientific subjects, such as black holes, relativity and quantum mechanics. And when sharing his thoughts on presumptive GOP nominee Donald Trump, Hawking used a math term to deride the “demagogue” and his supporters.

Appearing Monday on British TV network ITV, Hawking said Trump “is a demagogue who seems to appeal to the lowest common denominator.” While in math, “lowest common denominator” is the smallest multiple by which a set of fractions can be divided, colloquially the phrase mocks the intelligence of the group described.