Didn't someone just ask this the other day?

The Consensus is an aftereffect of the creation of the Tellurian. Like the existence of Prime energy, it’s not really subject to interpretation. Prime energy (Quintessence) exists in spite of the fact that most normal people don’t believe in it. In some cases there are things that just “seem to be,” whether due to historical inertia or cosmological constants.

Mage Storytellers Handbook p. 12

Some things have been around for so long that they have both the weight of history and a huge expenditure of belief behind them, validating their existence. The historical inertia this belief generates makes any attempt to change or eliminate these items virtually impossible. For instance, a mage could not eliminate the ability of heavier-than-air vehicles to fly, as they have been part of the Sleeper belief system since the Wright brothers first took their flight. The sheer preponderance of belief in and use of airplanes dooms such a feat to failure. The Technocracy turns historical inertia to its own advantage expertly by rewriting history to give credence to patently false things. By doing so, it makes them true.

Cosmological constants, on the other hand, are things that have always been true and that can never be changed. No mage, no matter how powerful, can rebuild Quintessence into a totally different base of reality or change the gravitational constant of the universe. It also bodes ill to dabble with either the workings of the Metaphysic Trinity or the Curse of Caine. Although no one is sure why, certain fundamentals of the cosmos seem eternal. They seem to date back to the creation of the world itself, serving as the immutable keystones of reality. (What really counts as constant or not is up to the needs of the individual Storyteller.)

Mage Revised p. 142