Can't think of a good word or term to describe not feeling or thinking [closed]

An embryo hasn't yet developed sentience.

sentient condition or character; capacity for sensation or feeling.


I might give "insensate" a try and see if you like it.

ADJECTIVE

  1. Lacking physical sensation.

‘a patient who was permanently unconscious and insensate’

1.1 Lacking sympathy or compassion; unfeeling. ‘a positively insensate hatred’

  1. Completely lacking sense or reason. 2

‘insensate jabbering’


Per enxaneta's comment, both consciousness and awareness would fit. For consciousness, meanings 1 and 3 both work:

  1. the state of being conscious; awareness of one's own existence, sensations, thoughts, surroundings, etc.

...

  1. full activity of the mind and senses, as in waking life

Awareness carries mostly the same meaning, but has broader connotations:

the state or condition of being aware; having knowledge; consciousness

Consciousness in particular is associated with self-awareness, which may be narrower than you want. In that case, awareness (or one of the other answers here) might fit better.