What follows has nothing to do with secular humanism and everything to do with the nature of the one who says "I" am a (whatever).
(my bold emphasis)
"Secular humanism is philosophically naturalistic. It holds that nature (the world of everyday physical experience) is all there is, ..."
(I say) Thus a non-physical self or sense of self must be non-existent (not there).
"... and that reliable knowledge is best obtained when we query nature using the scientific method...."
(I say) This "self" can not be revealed, refuted, or confirmed by science. Are we all deluded by a non-existent illusion?
"... Naturalism asserts that supernatural entities like God do not exist, and warns us that knowledge gained without appeal to the natural world and without impartial review by multiple observers is unreliable."
(I say) My obvious internal, self-evident (needs no outside verification), and non-negate-able knowledge of "I am", though unseen by others, does not need proof or verification.
"I am" is a priori fact. That anything else exists needs to be demonstrated, verified. The knowledge of the world needs to gained.
I have never known myself to be non-existent but did exist as conscious-being before I first saw or knew the world (sounds heard within the womb)? Lack of memory is not demonstration of non-existence during that memory lapse period.
The question to be answered is not when did the universe begin?, but when did "consciousness" begin?
The unanswerable question is "Explain the world in the absence of consciousness?"
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