There are three words that often cause mystification – kula, akula and kaulikī. These are the words frequently associated with Trika Philosophy. Kula and akula are also prefixed to sahasrāra to refer to the two terminal points in the path of kuṇḍalinī.
The Power of Śiva is known as kula. Abhinavagupta says in his master piece Tantrāloka (III.67), “She is Parāśakti, the highest power of Divine (Śiva) expands the kula of Akula deity as kaulikī, with whom Paramaśiva rests always.” To understand this explanation better, we should understand about two unique powers, Śiva and Śakti. Śiva is also known as Prakāśa, the Self-illuminating Light and by His Light, the universe is known. Śakti is also known as Vimarśa, who reflects the Light of Prakāśa and make the objects known. Only through Vimarśa, Prakāśa is made aware of. This also explains the interdependency of Śiva and Śakti. Kula, the power of Śiva manifests in the form of physical bodies, sense organs, mind, etc. In other words, kula is the stimulator of worldly process. Kula cannot be said as the cause, because cause is Prakāśa, also known as Śiva. Without Prakāśa, this stimulation or acceleration cannot happen.
Śiva is not the stimulator of the worldly process; yet He is the cause of the worldly process. But for him, stimulation cannot happen. In other words, Śiva causes stimulation of worldly process, not directly but through His Power, Parāśakti. This can be explained as the cause and effect phenomenon. Thus, all the dimensions of creation rest only in Akula (Śiva) without any intent to manifest. This is the state of non-differentiation between Śiva and Śakti. This stage is known as saṁvit, from which Śiva emanates as akula and from Śiva, Śakti emanates as Parā and is known asParāśakti. In the macrocosmic level, akula and kula are known as the Self (Brahman) and the self, the individual soul covered by māyā. The Self covered by the sheath of māyā is known as the self or individual soul. When māyā is realized, māyā goes away making us to realize the Self. Māyā is the veil caused by Parāśakti. In order to remove māyā, She needs to be realized first. Hence Śakti worship attains great importance. In the microcosmic level, akula becomes the soul and kula becomes kuṇḍalinī.
There are two sahasrāra-s according to Bhāvanopaniṣad (verse 9). One is known as kula-sahasrāra, which is situated below the mūlādhāra chakra, where Parāśakti in Her subtlest form kuṇḍalinī resides. Another is akula-sahasrāra, above sahasrāra. Akula-sahasrāra is also known as bindu. When one reaches bindu, which is also known as akula-sahasrāra, it means that he has transcendedmāyā. This happens only after Parāśakti is realized in Her full glory. This is the stage where nirvikalapa-samādhi unfolds.
However, the position of akula-sahasrāra and kula-sahasrāra are differently interpreted in certain other Tantra Scriptures.