But for people who struggle with doubts--the sick souls and Winter Christians I describe in The Authenticity of Faith--faith doesn't feel like that at all. Faith is not a solid yes or a solid no. Faith feels indeterminate. Like a yes and a no, going back and forth, back and forth. Faith is a yes always shadowed by that inner voice: "but on the other hand...". Sometimes faith is a yes and no at the same time.
Basically, for many of us faith feels like quantum superposition.
If you are not aware of quantum superposition it's a part of the weirdness regarding the behavior of the elementary particles of the cosmos, things like photons and electrons. Specifically, according to quantum mechanics, the reigning theory for how these particles behave, the exact location and momentum of these particles cannot be precisely specified. These features of a particle can only be known probabilistically. This is the famous Uncertainty Principle.
But it's weirder than that. It's not just that the exact location and momentum of these particles cannot be known with certainty. It's not simply that the particle has a 25% chance of being Here versus a 75% chance of being There. It's more like the particle's existence is both Here and There, at the same time, albeit with different probabilities.
Now, if that's hard to wrap your head around you're in good company. As the physicist Richard Feynman once quipped, "Anyone who says that they understand Quantum Mechanics does not understand Quantum Mechanics."
The notion that a particle can be both Here and There, at the same time, is called quantum superposition and it sits behind some of the stranger features of the quantum world, things like quantum entanglement. The Wikipedia definition of quantum superposition (emphasis added):
Quantum superposition is a fundamental principle of quantum mechanics that holds that a physical system—such as an electron—exists partly in all its particular theoretically possible states simultaneously; but when measured or observed, it gives a result corresponding to only one of the possible configuration.When measured, the wave-function of a particle (those probability estimates) collapses and we see the particle either Here or There. But prior to the observation the particle is, in a very real but weird way, both Here and There. And while it is true that any big object can't be both Here and There at the same time, it does appear that elementary particles can be in two places at the same time. That is quantum superposition.
And that is what I'm saying faith often feels like, like a quantum superposition.
True, at any given moment if I were to verbalize my beliefs, like taking the measurement of an elementary particle, "collapsing the wave-function of faith," my faith might be Here or There.
But in reality, in my moment to moment experiencing of faith, prior to any verbal description my faith feels like a quantum superposition--it's always both Yes and No, believing and doubting.
Both possible states--Here and There--simultaneously.