This has been compared with meditation on a bright object in the Visuddhimagga. Practitioners then visualize this image in front of themselves, and then move the mental image inwards through seven bases of the mind. Once the mental hindrances are overcome, the visual image imagined is transformed. Practitioners may also use a "mantra" () "Sammā-Arahaṃ", which refers to the Buddha who has 'perfectly' ("sammā") attained 'perfection in the Buddhist sense' ("arahaṃ"), as can be found in the traditional "Tiratanavanda" chant. This is a form of "Buddhanussati", i.e. recollecting the Buddha qualities. This mantra has also been used by monks from Northern Thailand. Alternatively, according to Wat Phra Dhammakaya, practitioners can also place the attention at the center of the body directly, and can even do so without visualizing or using a mantra. The first stage of this path Luang Pu Sodh simply called the 'beginning of the path' (). After that, Luang Pu Sodh would usually describe the level of attainment in terms of inner bodies ("") within every human being, which are successively more subtle, and come in pairs. In total, every human being consists of nine types of bodies, each of which has a normal and refined form. The first four pairs of these bodies are equated with the orthodox "jhāna" meditation attainments. Next is the 'change-of-lineage' () intermediary Dhammakaya state: this is the intermediate state between not being enlightened yet, and the four stages of enlightenment. The final four of these inner pairs are called the "Dhammakayas", and are equated with the four stages of enlightenment, leading to the final stage of enlightenment ("arahant"). After practitioners have attained the "Dhammakaya", they can gain insight into the reality of life through observation of their own physical and mental processes. It is believed they can understand birth, death and suffering at a deeper level, when they see the literal essence of these phenomena through meditative attainment. According to the Dhammakaya tradition, the Buddha made the discovery that nirvana is the true Self (). The tradition calls this true self the "Dhammakāya", the spiritual essence. The tradition believes that this essence of the Buddha and Nirvana exist as a literal reality within each individual.