अज्ञश्चाश्रद्दधानश्च संशयात्मा विनश्यति।नायं लोकोऽस्ति न परो न सुखं संशयात्मनः॥
ajñaś cāśraddadhānaś ca sanśayātmā vinaśyatināyaṃ loko ’sti na paro na sukhaṃ sanśayātmanaḥ
Word by word
The verse says
The one who does not know, who does not trust, whose self is made of doubt — he is lost. For the one made of doubt there is no this world, no other one, and no happiness.
In plain words
The counter-case, and it is the harshest sentence in the chapter.
Three conditions: not knowing, not trusting, and saṁśayātmā — a self made of doubt.
And the verdict has three parts: not this world, not the next, and no happiness anywhere.
Where you've felt this · in growing older
Someone has spent forty years unable to commit to any of it. They were never wrong about anything. They also never got to live in any of the lives they examined.
Going deeper
The phrasing is the thing to notice: saṁśayātmā — one whose very self is doubt. Not someone who has doubts.
That distinction carries the verse and it is the difference between a state and an activity. Doubting is how anyone thinks. Being constituted by doubt is a condition in which nothing can ever be tested, because testing requires provisionally proceeding.
The Gita is not attacking scepticism. 2.29 conceded that hearing this leaves you not knowing it. 4.34 prescribed paripraśna, thorough questioning. This is a text that keeps asking to be interrogated.
What it identifies is a posture in which the questioning has become the permanent residence.
The severity still deserves to be named. Vinaśyati — he is destroyed — is a hard verdict, and readers are entitled to find it too hard. It is worth reading it against 4.36, two verses earlier, where the worst of all wrongdoers is carried across. The Gita is stricter with the uncommitted than with the guilty, which is a strange and consistent feature of it.