A review essay concerning The Cambridge Companion to the Philosophy of Biology, David L. Hull and Michael Ruse, eds. (Cambridge: Cambridge University Press, 2007; xxviii + 513 pp.) and Philosophy of Biology, Mohan Matthen and Christopher Stephens, eds. (Amsterdam, Elsevier/North-Holland, 2007; xx + 618 pp.)    Informe sobre The Cambridge Companion to the Philosophy of Biology, David L. Hull y Michael Ruse, eds. (Cambridge: Cambridge University Press, 2007; xxviii + 513 pp.) y Philosophy of Biology, Mohan Matthen y Christopher Stephens, eds. (Amsterdam, Elsevier/North-Holland, 2007; xx + 618 pp.).