BG 14.13

अप्रकाशोऽप्रवृत्तिश्च प्रमादो मोह एव च ।
तमस्येतानि जायन्ते विवृद्धे कुरुनन्दन ॥१३॥

aprakāśo 'pravṛttiś ca
pramādo moha eva ca
tamasy etāni jāyante
vivṛddhe kuru-nandana

aprakāśaḥ - darkness; apravṛttiḥ - inactivity; ca - and; pramādaḥ - madness; mohaḥ - illusion; eva - certainly; ca - also; tamasi - the mode of ignorance; etāni - these; jāyante - are manifested; vivṛddhe - when developed; kuru-nandana - O son of Kuru.

Text

When there is an increase in the mode of ignorance, O son of Kuru, darkness, inertia, madness and illusion are manifested.

Purport

When there is no illumination, knowledge is absent. One in the mode of ignorance does not work by a regulative principle; he wants to act whimsically, for no purpose. Even though he has the capacity to work, he makes no endeavor. This is called illusion. Although consciousness is going on, life is inactive. These are the symptoms of one in the mode of ignorance.

Bhagavad Gita As It Is.

Chapter 14: The Three Modes Of Material Nature. Text 13

When there is an increase in the mode of ignorance, O son of Kuru, darkness, inertia, madness and illusion are manifested.