The Shurangama Sutra is the Sutra for opening up wisdom, so much so, that the great Zen/Chan Master Hsu Yun only wrote a commentary to 1 Sutra in his entire lifetime of 120 years – the Shurangama Sutra.

It’s important to reflect on what the Buddha is trying to teach here because it is directly applicable to your meditation. It’s important to actually use this understanding how your mind works and use this as a basis for your meditation.

Ānanda said to the Buddha,

“World-Honored One, if the wondrous enlightened nature is indeed not dependent on causes and conditions, why then has the Buddha often taught the monks that our visual awareness requires four conditions to be present:

Space Light Mind and The eye-faculty.

“What did you mean then?”

The Buddha questions Ananda, “What is seeing? What is not being able to see?”

The Buddha said,

“Ānanda, what I have said about causes and conditions as they function in the world is not an ultimate truth. I have another question for you, Ānanda. When ordinary people say,

‘I see’ or

‘I do not see,’

“What do they mean by ‘seeing’ and ‘not seeing’?”

Ananda answers “You need light to be able to see. If there’s no light, you can’t see”.

Ānanda said,

“Relying on the light of the sun, of the moon, or of lamps, ordinary people can see various objects. That is what they mean by ‘seeing.’ Without at least one of these three sources of light, they would not be able to see.”

The Buddha says that’s not true because even if pitch darkness – you still “see” the darkness – you are still aware of the darkness in front of you.

“Ānanda,

If people cannot see when light is absent, they would have no visual awareness of total darkness.

Since they are visually aware of total darkness, you cannot say that they cannot see in the absence of light.

Further, IF you say that you can’t see when there is no light (i.e., you can’t see when there is darkness), then you wouldn’t be able to see darkness when a light is present.

Further, if their inability to see light when they are in total darkness indeed means they cannot see when it is dark,

Then conversely, their inability to see darkness when it is light must also mean that they cannot see when it is light,

since the cases are parallel and both involve instances of not seeing.

Light and Dark are Dualistic Phenomena that you are aware of. But your visual awareness is not dependent upon either light or dark to be in front of it whatsoever – it still functions, regardless of whether light or darkness is in front of it.

“Light and darkness are mutually exclusive; still, regardless of which one is present, your visual awareness does not lapse for an instant. Therefore you should understand that in both cases there is seeing. How can you say that there is not?

“You should understand then that:

When people see light, their awareness of it does not come into being because of the light.

When people see darkness, their awareness of it does not come into being because of the darkness.

Your Visual Awareness also keeps functioning regardless of whether space or a solid object is in front of it. All these things – light and dark, space and solid objects – are dualistic phenomena that the visual awareness perceives.

When people see space, their awareness of it does not come into being because of the space, and

When people see solid objects, their awareness of them does not come into being because of the solid objects.

Source: The italicized text above is extracted from the latest version English version of the Shurangama Sutra:

A New Translation Buddhist Text Translation Society. The Śūraṅgama Sūtra With Excerpts from the Commentary by the Venerable Master Hsüan Hua (Kindle Locations 1803-1818).