The mind consciousness has a great power of discernment regarding the object of direct perception

For example, when the mind consciousness thinks of a square moon, a square moon appears in the brain; but when looking at the round moon in the sky and then trying to imagine that the moon before one's eyes is square, one simply cannot imagine a square moon. This is because the mind consciousness lacks sufficient meditative concentration (samādhi) and is disturbed by the state of the present object, making it very difficult to engage in clear erroneous cognition (non-valid cognition) and imagination.

With the eyes open, what the mind consciousness perceives is the mental sense-object (dharma-object) upon the five sense-objects; with the eyes closed, what the mind consciousness imagines is the Image-Only Object. If, with the eyes open, one sees the round moon upon the five sense-objects, after the mental consciousness accompanying the five sense consciousnesses has discriminated the round moon, and with the direct perception of the eye consciousness in coordination, the power of what is personally witnessed is strong, and the manas can confirm and support it. After seeing the round moon, it then becomes very difficult to imagine a square moon, because the image of the round moon remains in the mind consciousness. The mind consciousness would have to discriminate two states of object simultaneously, so the conscious mind is divided, and the imaginative function it gives rise to becomes very weak; imagining a square moon is therefore not easy.

The solitary mental consciousness is the most easily disturbed, so the capacity to imagine a square moon is insufficient. After all, the solitary mental consciousness discriminates through erroneous cognition (non-valid cognition), with relatively few external conditions; the round moon is discriminated through direct perception, and with the eye consciousness discriminating it simultaneously, the force of imagining the round moon is great, so it is somewhat more difficult for the Image-Only Object to manifest. Therefore, the square moon in the mind does not easily appear.

If the mind consciousness has exceptionally good meditative concentration, the solitary mental consciousness may gain the upper hand, and one can then imagine a square moon in the mind, which contradicts the moon upon the material sense-object. At this time, the round moon and the square moon may appear alternately—now round, now square. A person with extremely good meditative concentration may be able to manifest both moons simultaneously, or may manifest only a single square moon. Try practicing your own meditative concentration and see which consciousness can gain the upper hand. If this kind of meditative concentration can be cultivated, then in the future one will be able to transform all dharmas, and even manifest a trichiliocosm within a single thought. Healing and adjusting others' illnesses also depends entirely on this kind of meditative concentration, and changing others' minds likewise depends entirely on this kind of meditative concentration.