In short, the proofs are many that go to show that despite the loss of reason, the power of the soul would still continue to exist.

‘Abdu’l-Bahá, Bahá’í World Faith, p. 337-338

The report from . . . indicates that the . . . old believer is not always lucid apparently suffering from Alzheimers disease. Whether this individual is able to serve on the Assembly will depend on the degree to which he is able to understand what is being discussed and participate.  The brief compilation of Writings on mental illness . . . will hopefully assist the friends to clarify whether the elderly believer could be considered for Assembly membership.

NSA of the Bahá’ís of Canada, to the Bahá’í Council of British Columbia and Yukon, 25 February 2000