and no destination' - these people are well on their way to gaining some new discoveries and 'advancing' our race, but still sailing nowhere. 'and the bright ship humana is well on its way with grave determination.

they are still restricted by their old beliefs that they wont allow to be changed, but still looking for new answers.

'with their candlesticks and compasses' - because (metaphorically) they are searching in the dark.

'the flat earth society is somewhere far away' - these people are far off ('away') from getting anywhere. There is no destination because these discoveries have no limit, nor a real purpose. It is 'sent far away with grave determination' because these are the people who push the human race forwards (scientists or whatever), always determined to make new discoveries, looking into the unknown ('far away') for their answers. 'the bright ship humana is sent far away with grave determination and no destination' - everyone who is able to accept is the 'bright ship humana'. 'the flat earth society is meeting here today, singing happy little lies' - the flat earth society is just meant to mean everyone who (in our present day) still thinks like these people unable to accept new ideas. This was later proven false, but when first discovered Columbus was shunned upon by people unable to accept this. 'the flat earth society' and 'the bright ship humana' - back in the day, people thought the earth was flat.

Flat earth society lyrics