Vaisesika Sūtra 5.2.17

अपसर्पणमुपसर्पणमशितपीतसंयोगाः कार्यान्तरसंयोगाश्चेत्यदृष्टकारितानि ॥१७॥

apasarpaṇam upasarpaṇam aśitapītasaṁyōgāḥ kāryāntarasaṁyōgāś cētyadṛṣṭakāritāni ॥17॥

[अपसर्पणम् (apasarpaṇam) - withdrawal; उपसर्पणम् (upasarpaṇam) - approach; अशित-पीत-संयोगाः (aśita-pīta-saṁyōgāḥ) - combinations of eaten and drunk; कार्य-अन्तर-संयोगाः (kārya-antara-saṁyōgāḥ) - combinations with other effects; च-इति (ca-iti) - and thus; अदृष्ट-कारितानि (adṛṣṭa-kāritāni) - caused by unseen force;]

Withdrawal, approach, eating-drinking combinations, and other functional conjunctions are caused by the unseen-force.