The use of koans in Seon (Zen) practice holds great significance as it is a central aspect of the meditative tradition. Koans are paradoxical statements or questions that are used as a tool for contemplation and reflection in order to reach a state of enlightenment.

One of the main purposes of koans in Seon practice is to challenge the logical and rational thinking of the practitioner. In Seon, it is believed that the mind is the root of all suffering and that by breaking free from the limitations of logical thinking, one can attain a state of enlightenment. Koans serve as a means to disrupt the habitual thought patterns and open the mind to new possibilities.

Another significant aspect of koans is their ability to point towards the truth beyond words and concepts. In Seon, it is understood that ultimate reality cannot be expressed through language or concepts, as they are limited and dualistic. Koans, on the other hand, are meant to transcend language and directly point towards the truth, allowing the practitioner to experience it for themselves.

Furthermore, koans are used as a means of testing and deepening the understanding of the practitioner. In Seon, it is believed that true understanding can only come from direct experience and not from intellectual knowledge. Koans serve as a way to test the practitioner's understanding and push them to go deeper in their contemplation and meditation.

The use of koans also encourages a sense of self-inquiry and introspection. In Seon practice, the focus is on self-discovery and understanding one's true nature. Koans serve as a catalyst for this process by challenging the practitioner to look within and question their own beliefs and perceptions.

Lastly, the use of koans in Seon practice is rooted in the idea of non-attachment. In order to reach a state of enlightenment, one must let go of all attachments and desires. Koans, with their paradoxical nature, help to break down the dualistic thinking and attachments of the mind, leading the practitioner towards a state of non-attachment.

In conclusion, the use of koans in Seon practice has multiple layers of significance. They challenge the logical thinking of the mind, point towards the truth beyond words, deepen understanding, encourage self-inquiry, and ultimately lead towards a state of non-attachment and enlightenment.