Wonhyo 元曉 (617-686) reads the principle of practice that runs throughout the Vajrasamādhi-Sūtra 金剛三昧經 as 'the practice of contemplating the mind that has but a single taste' 一味觀行. Considering the context of the term 'contemplation of the mind' 觀行 in Wonhyo's Commentary on the Vajrasamādhi-Sūtra, it appears he defines insight 觀 as a focus on intellectual awakening, and acquiring 行 as active experiential learning where changing the mind-aspect is the critical component. There are two important matters of note in this practice of contemplating the mind. The first is that the combination of insight 觀 and acquiring 行 comprise the system of Seon 禪 practice to attain samādhi 三昧, and the second is that insight and learning through experience are interfused in 'the practice of contemplating the mind that has but a single taste' 一味觀行. In other words, Wonhyo sets intellectual understanding to be one pillar of attaining samādhi, while simultaneously interconnecting the practices of intellectual insight 觀 and acquiring through experiential learning 行. The union of insight 觀 and acquiring 行 is also seen in Wonhyo's explanation of entering into enlightenment through two ways 二入. According to Wonhyo, securing intellectual insight and understanding of Buddha-nature 佛性, and to be freed from the hallucinatory image of subject and object conception 相 in the mind-aspect, are the two conditions to accomplish Vajrasamādhi 金剛三昧, the step that immediately precedes the completion of enlightenment. A characteristic point of Wonhyo’s view of Seon 禪 is his emphasis on the union of samādhi and interaction with society. According to Wonhyo’s opinion in his Commentary on the Vajrasamādhi-Sūtra 金剛三昧經論, a practitioner who wants to be enlightened must have the capability to maintain the brightness of wisdom and the serenity of existence acquired through samādhi 三昧, while interacting with society. The development of the capability of intellectual reflection is an essential precondition of unifying the results of samādhi 三昧 and worldly interaction. This viewpoint of Seon 禪 makes us critically introspect the traditional, commonly accepted views of Seon 禪 and samādhi 三昧, and presents a very beneficial and extremely important insight in investigating the original characteristics of Buddha’s contemplation.