Stoicism was the dominant philosophy of the Roman Republic and Empire. Stoics had a cosmology similar to the Law of One. Here are two quotes, the first is by Cicero, the last great defender of the Roman Republican system, just as it became the empire. The second is by Marcus Aurelius, the philosopher-king, and the last good emperor of Rome. He appears in the movie gladiator where he tried to restore the Republican system.
Quote:The universe itself is god and the universal outpouring of its soul; it is this same world's guiding principle, operating in mind and reason, together with the common nature of things and the totality that embraces all existence; then the foreordained might and necessity of the future; then fire and the principle of aether; then those elements whose natural state is one of flux and transition, such as water, earth, and air; then the sun, the moon, the stars; and the universal existence in which all things are contained.
—Cicero, De Natura Deorum, i.
Quote:Constantly regard the universe as one living being, having one substance and one soul; and observe how all things have reference to one perception, the perception of this one living being; and how all things act with one movement; and how all things are the cooperating causes of all things that exist; observe too the continuous spinning of the thread and the structure of the web.
—Marcus Aurelius, Meditations, iv. 40.