What Is a Spirit?

Does spirit just consist of breath, That natural inspiration That starts at birth and ends with death, A lifetime's animation? Each spirit lasts a certain time, Its precious share of being, A span so fragile yet sublime, So very quickly fleeing. Eternal life is troubling, To rational minds, deluded, As, taught by Nature, everything Must end, ourselves included. But spirits will keep right on growing, Even as aging bodies fail, And learning, understanding, knowing, Remain life's peerless holy grail. Spirit's a smile, a thought, a dream, A deepening friendship treasured, A book, a song, a stray moonbeam, Too precious to be measured.