The theory of algebraic cycles encompasses such central problems in mathematics as the Hodge conjecture and the Bloch-Kato conjecture on special values of zeta functions. Spencer Bloch's landmark lectures, first published in 1980, are still the best place to learn the guiding philosophy of algebraic cycles and motives.
Spencer Bloch's landmark lectures are finally back in print, with a new preface by the author reflecting on recent developments.